Commit 83bfbd0bb9 ("cifs: Remove the RFC1002 header from smb_hdr")
changed the quantity this bound is measured against. It used to be
srv->total_read minus the 4-byte RFC1002 preamble that total_read then
included, so it was the SMB message length. The same commit stopped
counting the preamble, and the mechanical substitution to
srv->total_read - srv->pdu_size left an expression that is identically
zero: standard_receive3() reads MID_HEADER_SIZE() bytes and then exactly
pdu_length - MID_HEADER_SIZE() more, adding both to total_read.
len is therefore 0, the subtraction below it wraps, and no __u32
DataOffset can exceed the result, so the check from commit 097f5863b1
("cifs: read overflow in is_valid_oplock_break()") no longer rejects
anything. Use total_read, which is now the message length on its own.
Fixes: 83bfbd0bb9 ("cifs: Remove the RFC1002 header from smb_hdr")
Cc: stable@kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
When the else branch of cifs_file_set_size() finds a writable file handle
via find_writable_file(), it borrows tcon and server from the handle's
tlink, attempts the handle-based set_file_size() RPC, and then releases
the handle with cifsFileInfo_put().
If set_file_size() fails, execution falls through to the path-based
fallback, which reuses the borrowed tcon and server under the
"if (tcon == NULL)" guard. Since tcon is not NULL at that point, the
guard is skipped. If cifsFileInfo_put() dropped the last reference on a
tlink that was already removed from the tlink tree (TCON_LINK_IN_TREE
cleared, as happens during reconnection or session teardown),
cifs_put_tlink() will have freed tcon; the subsequent set_path_size()
call is then a use-after-free.
Setting tcon = NULL after cifsFileInfo_put() causes the existing guard
to take the cifs_sb_tlink() path, which acquires a fresh reference for
the path-based operation or fails cleanly if the session is gone.
Fixes: 110fee6b9b ("smb: client: fix missing timestamp updates with O_TRUNC")
Cc: stable@vger.kernel.org
Cc: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
TCP_Server_Info contains a preauth_sha_hash[] and a cryptkey[] array
that might contain sensitive data. Thus free its memory with
kfree_sensitive() to avoid that we are leaking this information to
the heap.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Make sure to not leak signature data via the stack, clear it
with memzero_explicit() before leaving the function.
To avoid that we have to introduce "goto"-cleanup here, we re-arrange
the code a little bit (and drop the commented cifs_dump_mem debug
code that looks like a leftover from very early days).
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Make sure to not leak hash data via the stack, clear it
with memzero_explicit() before leaving the function.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Make sure to not leak key-related data via the heap or the stack
by using kfree_sensitive() or memzero_explicit() here.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Sensitive data like keys that are stored in stack-local arrays could
be leaked via the stack to the calling functions. There is no known
vulnerability for this right now, but it's good security style to
explicitly zeroize this sensitive material as soon as possible to
avoid that it could be exploited together with other bugs later.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
This reverts commit 6d9a4aaaa8.
First, directly flushing fileinfo_put_wq in that commit cannot guarantee
that all in-flight I/O has run its cleanup_work on system_dfl_wq and
subsequently called queue_work(fileinfo_put_wq, ...). Flushing only the
latter workqueue may therefore miss puts that have not yet been queued, so
the fix is not reliable in the first place. Moreover, this fix flushes
inside cifs_umount(), which means the busy-dentry warning can still be
triggered when umount_check() is called inside kill_anon_super(), because
kill_anon_super() is executed before cifs_umount().
Second, commit 75f5c412fa ("smb: client: fix busy dentry warning on
unmount after DIO") already drains both serverclose_wq and fileinfo_put_wq
in cifs_kill_sb(), before kill_anon_super(). By adding a per-superblock
outstanding-rreq counter, it guarantees that all cleanup_work for this sb
have run, and thus all relevant cfile puts are queued on fileinfo_put_wq
or serverclose_wq.
Third, no path between those drains and cifs_umount() can queue new work
onto either workqueue. In the "cifs_sb->root == NULL" path there are no
file-related workers either, so that case is safe as well.
Therefore the busy-dentry and null-ptr-deref problems cannot arise, and
the flush added by commit 6d9a4aaaa8 ("cifs: remove all cifs files before
kill super") is redundant and can be removed.
Signed-off-by: Zizhi Wo <wozizhi@huawei.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
reparse_buf_ptr() reads buf->ReparseDataLength before checking that
count covers the full fixed header:
buf = (struct reparse_data_buffer *)((u8 *)io + off);
len = sizeof(*buf); /* 8 bytes */
rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */
if (count < len || count < rdlen + len) /* check comes after */
struct reparse_data_buffer has ReparseDataLength at offset 4. If a
server returns OutputCount < 6, the read at offset 4-5 reaches past
the end of the received data. The off+count bounds against iov_len
were already validated, but that does not protect against count being
smaller than sizeof(*buf).
Split the check: verify count >= sizeof(*buf) before reading
ReparseDataLength, then verify count covers the data region.
Fixes: a158bb66b137 ("smb: client: optimise reparse point querying")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
The check added by commit 7d9a7f1f96 ("smb/client: fix possible
infinite loop and oob read in symlink_data()") compared the post-ALIGN
length against the remaining buffer, but ALIGN() itself can overflow:
for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8)
wraps to 0, so the subsequent bounds check passes, and the loop
advances by zero bytes leaving 'p' pointing into stale data.
Fix by checking the raw ErrorDataLength against the remaining space
before applying ALIGN(), then checking again after. Since raw_len is
bounded by the buffer, raw_len + 7 cannot overflow, so the second check
is an exact post-alignment bounds guard.
Fixes: 76894f3e2f ("cifs: improve symlink handling for smb2+")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Use the convenient 'strreplace()' to simplify
'__build_path_from_dentry_optional_prefix()'.
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
When a valid primary TRANSACT2 response has been received (mid->resp_buf
set, mid->multiRsp true) and a subsequent secondary response causes
cifs_check_trans2() to return false -- either because the SMB header is
invalid (malformed != 0) or because check2ndT2() rejects the PDU --
handle_mid() overwrites mid->resp_buf with the new buffer (leaking the
primary buffer) and, because mid->multiRsp is set, skips the
server->smallbuf/bigbuf NULL-out. When the user thread frees
mid->resp_buf, server->smallbuf or server->bigbuf is left dangling; the
demux thread reuses it for the next packet, resulting in a use-after-free.
Combine both early-exit conditions and, when mid->multiRsp is already
set, abort the pending transaction inline: set multiEnd, call
dequeue_mid() with malformed=true, and return true so handle_mid() exits
without touching mid->resp_buf or the server buffer pointers.
Fixes: 316cf94a91 ("CIFS: Move trans2 processing to ops struct")
Cc: stable@vger.kernel.org # cifs_check_trans2() is in smb1ops.c on kernels < 7.0
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
coalesce_t2() computes data pointers directly from server-supplied
DataOffset fields with no validation against buffer bounds:
data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +
get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);
data_area_of_src = (char *)&pSMBs->hdr.Protocol +
get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);
data_area_of_tgt += total_in_tgt;
...
memcpy(data_area_of_tgt, data_area_of_src, total_in_src);
A small DataOffset can push a pointer below the actual byte area,
overwriting header fields; a large one can push it past the buffer
end, causing out-of-bounds heap reads (source) or writes (target).
The BCC overflow guard does not prevent this: BCC reflects how much
data is present, while DataOffset controls where in the buffer it
starts.
The "validate target area" comment present since the function was
first written in 2005 was a placeholder that was never implemented.
Add lower- and upper-bound checks for both data pointers before the
memcpy, and before any target header fields are modified.
Fixes: e4eb295d38 ("[PATCH] cifs: Handle multiple response transact2 part 1 of 2")
Cc: stable@vger.kernel.org
Reported-by: Shen Yongchao <grayhat@foxmail.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
cifs_open_info_data stores FILE_ALL_INFORMATION and SMB3 POSIX query
information in a union. reparse_info_to_fattr() selects a union member
from the mount mode, while several directory checks always read
fi.Attributes.
The metadata can instead come from an SMB2 CREATE response on a POSIX
mount, or from a POSIX query while processing a reparse point. In those
cases the mount mode and hard-coded fi accesses select the wrong union
member.
See the procedures below:
cifs_nt_open
smb2_open_file
SMB2_open
data->fi = SMB2 CREATE response
data->contains_posix_file_info = false
cifs_get_inode_info
reparse_info_to_fattr
if (tcon->posix_extensions) // true
smb311_posix_info_to_fattr
data->posix_fi // wrong union member
smb311_posix_get_fattr
smb2_query_path_info
smb2_compound_op
data->posix_fi = SMB3 POSIX query response
data->contains_posix_file_info = true
reparse_info_to_fattr
data->fi.Attributes // wrong union member
Add a common DOS attribute accessor and use contains_posix_file_info
both for attribute reads and for the final fattr conversion.
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
contains_posix_file_info describes the metadata stored in the
fi/posix_fi union. GET_REPARSE and QUERY_WSL_EA do not update that
union, so clearing the flag while processing those responses can make
POSIX metadata look like FILE_ALL_INFORMATION.
Set the flag when CREATE or a validated query response actually
populates the union, and leave it unchanged for auxiliary compound
operations. This also avoids changing the type when a query fails
before copying any metadata.
The issue can be reproduced against a Samba server with SMB3 UNIX
extensions enabled:
mount -t cifs //<server>/<share> /mnt/cifs \
-o vers=3.1.1,posix,reparse=nfs,actimeo=0
mkfifo /mnt/cifs/test-fifo
umount /mnt/cifs
mount -t cifs //<server>/<share> /mnt/cifs \
-o vers=3.1.1,posix,reparse=nfs,actimeo=0
stat -c '%F %s' /mnt/cifs/test-fifo
Before this change, stat reports "fifo 1024" although the server-side
EOF is zero. After this change, it reports "fifo 0".
Fixes: 9df23801c8 ("smb311: failure to open files of length 1040 when mounting with SMB3.1.1 POSIX extensions")
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Several SMB1 fallback and open responses do not provide the hard link
count. The SMB2 create-only query fallback has the same limitation.
These paths currently leave a zero link count or synthesize a value of
one and then expose it as authoritative metadata.
Mark those results with unknown_nlink so existing inodes keep their
cached link count and new inodes receive the usual sane default.
This was tested against Samba with "server min protocol = NT1". Mount
the share using SMB1 with Unix extensions disabled:
mount -t cifs //<server>/<share> /mnt/cifs \
-o username=<user>,vers=1.0,nounix
Create three names for the same inode and cache its real link count:
TESTDIR=/mnt/cifs/nlink-repro-$$
mkdir "$TESTDIR"
touch "$TESTDIR/file1"
ln "$TESTDIR/file1" "$TESTDIR/file2"
ln "$TESTDIR/file1" "$TESTDIR/file3"
stat -c 'before open: %h' "$TESTDIR/file1"
Open the file and read the link count through the open descriptor:
exec 3<"$TESTDIR/file1"
stat -Lc 'after open: %h' /proc/$$/fd/3
exec 3<&-
Clean up the test files:
rm -f "$TESTDIR/file1" "$TESTDIR/file2" "$TESTDIR/file3"
rmdir "$TESTDIR"
Before this change, the two stat commands report 3 and 1 because the
SMB1 open response overwrites the known link count. With this change,
both commands report 3.
Signed-off-by: Ze Tan <tanze@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
The code to clear the 'fastest_cmd' statistics has a typo that
repeatedly clears the stat for cmd 0, rather than iterating
through each cmd. Fix the typo (0->i).
Fixes: 433b8dd767 ("SMB3: Track total time spent on roundtrips for each SMB3 command")
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Reproducer:
1. server: systemctl start ksmbd
2. client: mount with `posix` option
mount -t cifs -o posix //${server_ip}/export /mnt
3. client: touch /mnt/file1 /mnt/file2
4. client: C program: int fd = open("/mnt/file2", O_RDONLY);
5. client: C program: rename("/mnt/file1", "/mnt/file2");
6. client: C program: struct stat stbuf; fstat(fd, &stbuf);
stbuf.st_nlink is 1, should be 0
This patch fixes xfstests generic/035 when mounted with `posix` option.
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Commit 110fee6b9b ("smb: client: fix missing timestamp updates with
O_TRUNC") introduced cifs_file_set_size(), which calls netfs_resize_file()
and cifs_setsize() on success. cifs_setsize() calls i_size_write(),
updating i_size to the new value. The subsequent blocks in both
cifs_setattr_unix() and cifs_setattr_nounix():
if ((attrs->ia_valid & ATTR_SIZE) &&
attrs->ia_size != i_size_read(inode)) {
truncate_setsize(inode, attrs->ia_size);
netfs_resize_file(&cifsInode->netfs, attrs->ia_size, true);
fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
}
are therefore unreachable on the success path: attrs->ia_size ==
i_size_read(inode) always holds after cifs_file_set_size() succeeds.
On the failure path, execution jumps to out/cifs_setattr_exit before
reaching these blocks.
truncate_setsize() and netfs_resize_file() are redundant with what
cifs_file_set_size() already did; fscache_resize_cookie() was moved there
by commit fa724e235c ("cifs: add fscache_resize_cookie() to
cifs_setsize()"). Remove both dead blocks.
Fixes: 110fee6b9b ("smb: client: fix missing timestamp updates with O_TRUNC")
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Huiwen He <hehuiwen@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
cifs_remap_file_range() acquires i_rwsem on both inodes via
lock_two_nondirectories() before calling smb2_duplicate_extents().
cifs_setsize() (called inside smb2_duplicate_extents() when the clone
extends the file) therefore already runs under the lock, meaning the
fscache_resize_cookie() added to cifs_setsize() by commit fa724e235c
("cifs: add fscache_resize_cookie() to cifs_setsize()") is correctly
serialised for this path without further changes.
That same commit made the caller-side block:
if (rc == 0 && new_size > i_size) {
truncate_setsize(target_inode, new_size);
fscache_resize_cookie(cifs_inode_cookie(target_inode), new_size);
}
redundant: smb2_duplicate_extents() already performs the full size update
via cifs_setsize() when the operation extends the file. Remove the
now-dead block.
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Huiwen He <hehuiwen@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
cifs_setsize() calls fscache_resize_cookie() without holding i_rwsem.
When the fscache cookie is active (FSCACHE_COOKIE_IS_CACHING is set),
fscache_resize_cookie() performs a real resize that requires i_rwsem
held exclusively. If another file descriptor has the same inode open,
fscache_use_cookie() was already called from that cifs_open(), making
the cookie active. In that case, calling cifs_setsize() from
cifs_do_truncate() (invoked from cifs_open() without i_rwsem) races
against concurrent fscache I/O.
Strip fscache_resize_cookie() from cifs_setsize(), making it a pure
size/page-cache helper. Add cifs_resize_file_locked() for callers
that already hold i_rwsem: it calls netfs_resize_file() and
cifs_setsize(), then temporarily activates the cookie with
fscache_use_cookie() to perform the resize under the lock, then
deactivates it with cifs_fscache_unuse_inode_cookie(). Using
fscache_use_cookie() before the resize ensures correctness whether or
not another fd already holds the cookie active.
Switch cifs_file_set_size(), smb2_duplicate_extents(), and both size-
extension branches of smb3_simple_falloc() to the new wrapper; those
paths already hold i_rwsem via VFS setattr, lock_two_nondirectories(),
or cifs_fallocate() respectively. cifs_do_truncate() continues to
call cifs_setsize() followed by cifs_invalidate_cache(), since it runs
without i_rwsem.
Fixes: fa724e235c ("cifs: add fscache_resize_cookie() to cifs_setsize()")
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
cifs_do_truncate() is invoked from cifs_open() without i_rwsem, so it
cannot use cifs_resize_file_locked() to perform a proper fscache cookie
resize. Instead, add cifs_invalidate_cache() after cifs_setsize().
cifs_invalidate_cache() calls fscache_invalidate(), which works without
holding i_rwsem: it unconditionally increments inval_counter and sets
FSCACHE_COOKIE_NO_DATA_TO_READ, ensuring that stale cached data is not
served once the cookie is later activated by fscache_use_cookie().
Truncation to zero leaves no valid cached data, making invalidation the
correct semantic here.
Fixes: fa724e235c ("cifs: add fscache_resize_cookie() to cifs_setsize()")
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
When free_tgts() frees all structures in ce->tlist, ce->tgthint
is left pointing to one of the freed cache_dfs_tgt structures.
If ce->tgthint is not reset before it is used later, it results
in a use-after-free.
Set ce->tgthint to NULL in free_tgts() after the elements are
freed to reflect that no elements remain.
Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Cc: stable@vger.kernel.org # depends on: smb: client: harden DFS cache against invalid target hints
Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Currently, get_tgt_name() returns ERR_PTR(-ENOENT) when ce->tgthint is
NULL, and dfs_cache_noreq_update_tgthint() assumes ce->tgthint is always
valid.
In preparation for clearing ce->tgthint in free_tgts(), harden callers
of get_tgt_name() against ERR_PTR results and harden
dfs_cache_noreq_update_tgthint() against NULL pointer dereferences.
Cc: stable@vger.kernel.org
Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
When a file has the setuid or setgid bit set and is written to, the VFS
strips those bits and issues a setattr with ATTR_KILL_SUID/ATTR_KILL_SGID
together with an ATTR_MODE carrying the already-cleared mode.
Both cifs_setattr_unix() and cifs_setattr_nounix() unconditionally dropped
ATTR_MODE in that case:
/* skip mode change if it's just for clearing setuid/setgid */
if (attrs->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attrs->ia_valid &= ~ATTR_MODE;
This is fine for the default mount, where the mode is only emulated via
the DOS read-only attribute and cannot represent the setuid/setgid bits
anyway. However, with the "cifsacl" or "modefromsid" mount options the
mode is stored on the server through an ACL (id_mode_to_cifs_acl()), with
the SMB3.1.1 POSIX extensions the mode is sent to the server directly,
and with the SMB1 Unix extensions (cifs_setattr_unix) the mode is sent
via CIFSSMBUnixSetPathInfo(). In all those cases dropping ATTR_MODE means
the cleared mode is never pushed to the server, so the setuid/setgid bit
survives the write.
This is a security issue: on local filesystems the setuid bit is stripped
when a file is written, but over these cifs.ko mounts the bit persists on
the server, potentially allowing an unexpected privilege escalation on
subsequent execution.
Fix this in two places:
1. cifs_setattr_nounix(): only take the "skip mode change" shortcut
when the mode is emulated via the DOS read-only attribute (i.e.
neither cifsacl/modefromsid nor the SMB3.1.1 POSIX extensions are
in effect), so that the cleared mode is propagated to the server
in the ACL / POSIX cases.
2. cifs_setattr_unix(): this function is only called when Unix
extensions are in effect, so the mode is always stored on the
server. Remove the shortcut entirely so that the cleared mode is
always pushed.
Fixes: d32c4f2626 ("CIFS: ignore mode change if it's just for clearing setuid/setgid bits")
Cc: stable@vger.kernel.org
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
smb2_async_readv() and smb2_async_writev() end with the same
send-error block: if the error is replayable and smb2_should_replay()
agrees, tell netfs to retry the subrequest. The write path also sets
wdata->replay. The read path does not set rdata->replay.
smb2_should_replay() is not a pure predicate. It consumes the retry
budget and computes the exponential back-off, doubling cur_sleep up to
CIFS_MAX_SLEEP. That back-off is only applied where the replay flag is
tested at the top of the reissued request:
if (rdata->replay) {
/* Back-off before retry */
if (rdata->cur_sleep)
msleep(rdata->cur_sleep);
smb2_set_replay(server, &rqst);
}
So on the read path the back-off is recomputed on every send-error
retry and then discarded, and SMB2_FLAGS_REPLAY_OPERATION is not set
on the reissued request.
netfs does not pace the retry either. netfs_reissue_read() calls
->issue_read() directly, and fs/netfs/read_retry.c contains no delay
of its own, so read send-error retries reissue immediately while the
equivalent write retries back off.
The read response callback already sets rdata->replay under the same
conditions, so the read path does use the replay mechanism. Only this
send-error path omits it.
Where the back-off belongs was settled while the commit below was
under review. David Howells asked whether netfslib should be doing the
back-off [1], and objected to sleeping inside the response callback
because that runs in the cifsd thread and would stall the socket [2].
The sleep was therefore taken out of smb2_should_replay() and moved to
just before the replay in smb2_async_readv() and smb2_async_writev()
[3]. Setting the flag here preserves that arrangement: the sleep still
happens at the top of the reissued request, not in a callback.
Set rdata->replay here, matching smb2_async_writev().
Fixes: 2c1238a747 ("cifs: make retry logic in read/write path consistent with other paths")
Link: https://lore.kernel.org/all/1652858.1769038134@warthog.procyon.org.uk/ [1]
Link: https://lore.kernel.org/all/1653031.1769038583@warthog.procyon.org.uk/ [2]
Link: https://lore.kernel.org/all/CANT5p=pXP3+CywpmK-on2uTvxO3S=31_B85_UDR7RoK1dQVtMA@mail.gmail.com/ [3]
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-5
Signed-off-by: Christopher Lusk <clusk@northecho.dev>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
smb2_new_read_req() allocates the request buffer with
smb2_plain_req_init() but only publishes it to the caller with
*buf = req at the very end of the function. Two error returns sit in
between:
rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, server,
(void **) &req, total_len);
if (rc)
return rc;
if (server == NULL)
return -ECONNABORTED;
[...]
rdata->mr = smbd_register_mr(server->smbd_conn,
&rdata->subreq.io_iter,
true, need_invalidate);
if (!rdata->mr)
return -EAGAIN;
On either of them the buffer is neither released nor handed back, so
it is leaked. The caller cannot clean up after it: smb2_async_readv()
does 'goto out' on a non-zero return, which skips the
cifs_small_buf_release(buf) at async_readv_out, and buf has not been
assigned at that point in any case.
The write path has never had this problem. smb2_async_writev()
registers the memory region inline and jumps to its release label
instead of returning:
wdata->mr = smbd_register_mr(...);
if (!wdata->mr) {
rc = -EAGAIN;
goto async_writev_out;
}
Commit b797209219 ("cifs: smbd: Retry on memory registration
failure") changed both sides from -ENOBUFS to -EAGAIN in a single
patch, which puts the two shapes next to each other.
Only the -EAGAIN return is reachable in practice, because
smb2_plain_req_init() calls smb2_reconnect() first and that already
fails with -EIO when server is NULL, before anything is allocated.
Both returns are given the same treatment here rather than leaving
one of them correct only by accident.
Because -EAGAIN is a replayable error, the failure also reaches the
retry block at the end of smb2_async_readv(), which marks the
subrequest NETFS_SREQ_NEED_RETRY, so a failing registration can be
retried rather than ending the I/O, and every attempt that reaches it
leaks another buffer. smb2_should_replay() short-circuits on
tcon->retry, so on a hard mount the attempt count is not bounded by
the retrans setting.
Only the asynchronous read path is affected. The synchronous
SMB2_read() caller passes rdata == NULL and the memory registration
block is guarded on rdata.
The memory registration failure path was pointed out by the Sashiko
AI reviewer while it was reviewing an unrelated patch to
smb2_async_readv().
Fixes: bd3dcc6a22 ("CIFS: SMBD: Upper layer performs SMB read via RDMA write through memory registration")
Link: https://sashiko.dev/#/patchset/20260729192002.876156-1-clusk%40northecho.dev
Link: https://lore.kernel.org/all/20260729192002.876156-1-clusk@northecho.dev/
Assisted-by: Claude:claude-opus-5
Signed-off-by: Christopher Lusk <clusk@northecho.dev>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Pull tracing fixes from Steven Rostedt:
- Fix use-after-free in eventfs_remove_rec()
The freeing of the eventfs_inode children used list_for_each_entry()
where the child is freed via srcu, but there's still a chance that it
gets freed. It should be using list_for_each_entry_safe().
- Fix eventfs_inode SRCU use of list in freeing
The iterator uses an SRCU protected list walk on the eventfs inodes.
The eventfs inode uses its "list" field in a union with the RCU list
head. When the inode gets added to the SRCU list it immediately
corrupts the list pointer and can cause an issue with the iterator.
Move the RCU list head to be shared with the children list head which
allows the iterator to check the parent inode if is freed before
referencing the child. Have the iterator check the parent "is_freed"
field and break out if it is set. Also add memory barriers to make
sure the ordering is correct.
- Fix various RCU synchronization issues with direct_functions
Updates to direct_functions have some missing RCU protection and
synchronization. Restructure the code a bit to make sure updates to
the direct_functions are protected.
- Remove an unneeded comma from a scope_guard()
There's a spurious comma in a scope_guard(). Remove it.
- Fix race in per CPU buffer swap in the ring buffer
When a per CPU buffer swap happens, it must make sure that it doesn't
occur while a writer is active. Instead it returns an -EBUSY. But
there's a small race window when a writer moves from one sub-buffer
to the next that it resets the "committing" counter. If a swap
happens at that moment, the buffer used for the commit of an event
will not match the buffer the event is actually on. Instead of using
the "committing" counter, use the recursive detection counter that
does not get reset when the writer crosses sub-buffers.
- Fix off-by-one in ftrace_free_mem()
The function ftrace_free_mem() gets an "end_ptr" as a parameter that
is exclusive to the rang to be freed. But its value is used to search
for the records that expects an inclusive value. Subtract one from
the parameter to convert it to an inclusive range.
- Disable resizing of the ring buffer for persistent buffers
Resizing the persistent buffer has undefined behavior. Prevent it
from being resized.
- Disable changing ring buffer subbuf order when resizing is disabled
The ring buffer subbuffer order can not be changed during resizing.
Use that instead of just checking if the buffer is mapped as mapped
buffers also have resizing disabled.
- Initialize subbuf_order of reader pages when they are created
In rb_allocate_cpu_buffer() the bpage->order is not updated to the
current subbuf_order leaving it as zero. This value is used when the
page is freed.
- Fix test_ringbuffer() to test for ERR_PTR before calling
kthread_stop()
The rb_threads[] array is assigned the output of kthread_run_on_cpu()
which could return an ERR_PTR. At the end of the test, all threads in
the array are cleaned up by kthread_stop() passing in the value in
the array if it isn't zero. But if the array contains an ERR_PTR,
kthread_stop() will not be able to handle it properly.
* tag 'trace-v7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix crash passing ERR_PTR to kthread_stop()
ring-buffer: Initialise reader page order in rb_allocate_cpu_buffer()
ring-buffer: Prevent subbuf order change when resizing is disabled
ring-buffer: Prevent resizing of persistent ring buffer
ftrace: Fix off-by-one fentry site disable in ftrace_free_mem()
ring-buffer: Use current_context for safe per-CPU buffer swap
ftrace: Drop extra comma in trace_buffered_event_enable
ftrace: Protect direct_functions in update_ftrace_direct_mod
ftrace: Protect direct_functions in update_ftrace_direct_del
ftrace: Protect direct_functions in ftrace_find_rec_direct
eventfs: Use children field for rcu head and add memory barriers
eventfs: Fix use-after-free in eventfs_remove_rec()
Pull s390 fixes from Vasily Gorbik:
- Fix potential uninitialized memory reads and buffer overflows from
malformed zcrypt CCA and EP11 requests by properly validating lengths
and payloads
- Fix possible out of bounds accesses in zcrypt EP11 domain handling by
replacing fixed payload layout assumptions with parsing ASN.1 fields
with bounds checks
- Fix zcrypt CCA and EP11 request and reply buffer allocations missing
required 4-byte padding, and scrub the full allocation on release
- Fix zcrypt CCA and EP11 messages leaking up to 3 uninitialized bytes
of memory by zeroing trailing alignment padding
* tag 's390-7.2-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/zcrypt: Pad trailing CCA or EP11 message with zeros
s390/zcrypt: Improve EP11 CPRB domain handling with ASN.1 parsing
s390/zcrypt: Improve EP11 CPRB length and overflow checks
s390/zcrypt: Improve CCA CPRB length and overflow checks
s390/zcrypt: Fix CPRB memory allocation in zcrypt misc code
In test_ringbuffer()'s out_free cleanup loop, the check
`!rb_threads[cpu]` only catches NULL entries and misses entries that
hold an ERR_PTR.
rb_threads[] is static, so unassigned slots are NULL. But when
kthread_run_on_cpu() fails for a cpu, it stores ERR_PTR(-ENOMEM) (or
-EINTR) in rb_threads[cpu] before the creation loop jumps to out_free.
That entry is non-NULL, so the old `!ptr` check does not break, and the
cleanup proceeds to call kthread_stop() on the ERR_PTR. kthread_stop()
then dereferences the bogus pointer, crashing the kernel during the
late_initcall self-test.
crash logs:
BUG: kernel NULL pointer dereference, address: 000000000000001c
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 7.2.0-rc6-dirty #7 PREEMPT(lazy)
RIP: 0010:kthread_stop+0x2e/0x220
RBX: fffffffffffffff4
CR2: 000000000000001c
Call Trace:
<TASK>
test_ringbuffer+0x1ec/0x650
do_one_initcall+0x6c/0x2c0
kernel_init_freeable+0x21d/0x420
kernel_init+0x15/0x1c0
ret_from_fork+0x21b/0x320
</TASK>
Kernel panic - not syncing: Fatal exception
Cc: stable@vger.kernel.org
Fixes: 64ed3a049e ("ring-buffer: make use of the helper function kthread_run_on_cpu()")
Link: https://patch.msgid.link/20260807154145.2846521-2-sh_def@163.com
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When a module's init text is freed, do_init_module() calls
ftrace_free_mem() with a half-open [start, end) range. However the
ftrace_cmp_recs() comparator treats the upper bound as inclusive, as all
its other users do, passing 'ip + size - 1'. So ftrace_free_mem() can
delete a record sitting exactly at 'end', which is outside the freed
range.
For a kernel without CFI or IBT, the first record of a function is at
the function start, which for the first function in a module is also the
base of its text allocation. As the module allocator packs its regions,
that address is often the 'end' passed by a neighboring module's
do_init_module(), causing the first function's ftrace location to get
disabled, preventing an attempt to livepatch it:
livepatch: failed to find location for function 'pcspkr_probe'
Convert the exclusive end to the inclusive 'end - 1' the comparator
expects, and return early for an empty range to avoid the subtraction
from underflowing when the init text size is zero.
Cc: stable@vger.kernel.org
Fixes: 42c269c88d ("ftrace: Allow for function tracing to record init functions on boot up")
Link: https://patch.msgid.link/1b5ccfa8095bdb1277f84af1c2c2e2205aca03ae.1785992188.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ring_buffer_swap_cpu() function currently checks the per-CPU
committing counter to determine if a buffer is actively being written to
before performing the swap. However, there exists a race window where
this check can be bypassed:
ring_buffer_lock_reserve
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_a
rb_reserve_next_event
rb_start_commit // inc committing
if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...}
__rb_reserve_next
rb_move_tail
rb_end_commit(cpu_buffer); // dec committing => 0
/* interrupt hits here, successfully swaps! */
local_inc(&cpu_buffer->committing);
ring_buffer_unlock_commit
cpu_buffer = buffer->buffers[cpu]; // cpu_buffer_b
rb_commit
rb_end_commit
RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))
// triggers warning
The committing counter can temporarily drop to 0 during a single write
operation (within rb_move_tail), creating a window where swap can
succeed even though the write is still in progress. This leads to
inconsistent buffer state and triggers the RB_WARN_ON in rb_commit().
Replace the committing counter check with current_context checks, which
are set at the entry of ring_buffer_lock_reserve() and remain valid
throughout the entire write operation, providing a reliable indicator of
buffer busy state during swap.
Cc: stable@vger.kernel.org
Fixes: 4239c38fe0 ("ring-buffer: Process commits whenever moving to a new page.")
Link: https://patch.msgid.link/20260803005640.2445666-2-wutengda@huaweicloud.com
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull x86 fix from Ingo Molnar:
- Fix MCE CMCI discovery initialization ordering bug (Breno Leitao)
* tag 'x86-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Set up the polling timer before CMCI discovery
Pull futex fix from Ingo Molnar:
- Fix race in futex_pivot_pending() during private hash resize
that can cause stuck tasks (Yao Kai)
* tag 'locking-urgent-2026-08-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Fix race in futex_pivot_pending() during private hash resize
Pull USB / Thunderbolt fixes from Greg KH:
"Here are some small USB and Thunderbolt driver fixes for 7.2-rc7 that
resolve some reported issues. Included in here are:
- new quirk for some broken USB devices
- thunderbolt device fixes for reported issues
- usb gadget driver fix
- usb atm driver fix
- xhci driver fixes.
- other minor USB driver fixes
All of these have been in linux-next this week with no reported
issues"
* tag 'usb-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: xhci: use BIT_ULL for CRCR bits to fix incorrect 64bit mask
usb: quirks: Add ShanWan gamepad to quirk list
usb: hub: Split announce_device() to log device identity before enumeration
usb: core: Add quirk for 255-bytes initial config read
usb: atm: cxacru: properly kill rcv_urb on error in cxacru_cm()
usb: misc: usbio: check ibuf_len against rxbuf_len in bulk msg
usb: gadget: f_ncm: Use unsigned int for ndp_index
usb: cdnsp: fix incorrect endian conversions for APB timeout register
thunderbolt: Initialize ->domain_released completion before it is being used
thunderbolt: icm: Preserve USB4 proxy data-valid bit
thunderbolt: Bound the DROM dual link port number before indexing sw->ports
thunderbolt: Fix bandwidth group reservation indexing
thunderbolt: stream: Unmap buffers with mapped size
Pull tty / serial / vt driver fixes from Greg KH:
"Here are some small serial and vt tty driver fixes for 7.2-rc7 that
resolve some reported problems. Included in here are:
- two vt core fixes
- amba-pl011 serial driver fixes
- 8250_of and 8250_dma driver fixes
- qcom-geni serial driver fix
- sc16is7xx serial driver fix
All of these have been in linux-next this week with no reported
issues"
* tag 'tty-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: amba-pl011: synchronize DMA teardown
serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ
serial: amba-pl011: fix indefinite RS485 post-send delay
vt: add permission check for KDSKBMETA ioctl
vt: stabilize tty reference in kbd_keycode with tty_port_tty_get
serial: 8250_of: clear stuck empty-FIFO RX-timeout on LPC32xx
serial: qcom-geni: fix TX DMA buffer flush
serial: 8250_dma: Clear stale RX state on shutdown
serial: sc16is7xx: enable THRI before filling TX FIFO
Pull staging driver fixes from Greg KH:
"Here are some more small staging driver fixes, just for the rtl8723bs
driver, for some reported problems found with it now that people are
starting to actually test the thing with "bad" networks.
Nothing major, but good to have in the -final release. All of these
have been in linux-next for over a week with no reported problems"
* tag 'staging-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: rtl8723bs: validate monitor transmit frame lengths
staging: rtl8723bs: fix missing shared-key auth challenge length check
staging: rtl8723bs: fix OOB read in WMM_param_handler()
staging: rtl8723bs: fix OOB read in rtw_get_wpa_ie()
Pull char / misc and documentation fixes from Greg KH:
"Here are some small char/misc and nvmem and documentation fixes for
7.2-rc7 to resolve some reported issues. Included in here are:
- updates to the documentation for the kernel threat model and
security bugs to get the LLMs to actually follow what we have been
asking them to do (i.e. not claim security issues for things we do
not consider security issues.)
- nvmem driver fixes which required a tiny "layout" driver to be
added.
- fastrpc driver fixes
- mei driver fix
- counter driver fix
- binder driver fix
All of these have been in linux-next this week with no reported
problems"
* tag 'char-misc-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
docs: security-bugs: clarify some mandatory steps for AI reports
docs: coding-assistant: explain important steps when looking for bugs
docs: security-bugs: clarify what counts as a valid version
docs: threat-model: move fake devices out of "non production use"
docs: threat-model: clarify "security bug" vs "vulnerability"
counter: microchip-tcb-capture: Fix DT channel validation
mei: pull kvfree out of spinlock
rust_binder: do not query current thread for all ioctls
nvmem: layouts: Add fixed-layout driver
nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI
misc: fastrpc: fix memory leak in fastrpc_channel_ctx_free
misc: fastrpc: fix channel ctx ref leak when session alloc fails
misc: fastrpc: take fl->lock when moving mmaps on interrupted invoke
misc: fastrpc: Remove buffer from list prior to unmap operation
misc: fastrpc: Fix initial memory allocation for Audio PD memory pool
Pull fbdev fixes from Helge Deller:
"A few patches for the core fbdev layer which stabilize or fix
potential issues with text font rendering after screen rotation or
after user initiated font changes and locking fixes for sysfb during
modifications of the graphics mode database"
* tag 'fbdev-for-7.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
fbdev: bitblit: bound-check glyph index in bit_cursor()
fbdev: Fix out-of-bounds access when rotating console after font resize
fbdev: core: Fix pointer desynchronization in fb_io_read()
fbdev: serialize mode sysfs access with lock_fb_info()
fbdev: clear fb_info->mode before deleting a videomode
fbdev: bound mode sysfs output to the sysfs buffer
When an eventfs inode is freed, it sets ei->is_freed and then uses its
ei->list to add it to the srcu link list as the list field is a union with
the rcu list head. As the ei->list is used to iterate over an SRCU
protected list without taking the eventfs_mutex, there's nothing stopping
the iteration over that list to see the ei->rcu instead of the ei->list
and it will read a corrupt target.
To fix this, change the union of the rcu list head with the children list.
On freeing the eventfs inode, set the is_free and execute a smp_wmb()
before adding the eventfs inode to the SRCU list.
On iteration of the ei->children list, at the start, execute a smp_rmb()
and then read the is_freed of the ei to see if the children list is still
valid. If is_freed is set, then the ei_child read is not valid and the
loop should exit immediately.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260808094215.4252430d@robin
Fixes: 704f960dbe ("eventfs: Read ei->entries before ei->children in eventfs_iterate()")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260806022719.375354-1-shuangpeng.kernel%40gmail.com
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
eventfs_remove_rec() recursively removes the child at the current loop
position. After the recursive call returns, list_for_each_entry() advances
by reading list.next from the removed child.
If free_ei() drops the final reference, release_ei() reuses the list/rcu
union to queue an SRCU callback. The child may be freed before that read.
The eventfs_mutex serializes list updates, but it does not keep the removed
child alive or prevent the SRCU callback from running.
Use list_for_each_entry_safe() to save the next sibling before recursively
removing the current child.
Cc: stable@vger.kernel.org
Fixes: 43aa6f97c2 ("eventfs: Get rid of dentry pointers without refcounts")
Link: https://patch.msgid.link/20260806022719.375354-1-shuangpeng.kernel@gmail.com
Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
