SG_GET_REQUEST_TABLE reports per-request diagnostic state through
sg_req_info::problem. The field is meant to indicate whether there is an
error to report for a completed request.
sg_fill_request_table() currently combines masked_status, host_status
and driver_status with bitwise AND. This only reports a problem when all
three status fields are non-zero at the same time. A normal target check
condition, for example, has masked_status set while host_status and
driver_status may both be zero, so the request is incorrectly reported
as clean.
Use the same condition as sg_new_read(), which sets SG_INFO_CHECK when
any of the three status fields is non-zero.
Cc: stable@vger.kernel.org
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/54B60C19F7DB8889+20260707030845.970018-1-raoxu@uniontech.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The parameter def_reserved_size defines the default buffer size reserved
for each Sg_fd and should be restricted to a range between 0 and 1,048,576
(see https://tldp.org/HOWTO/SCSI-Generic-HOWTO/proc.html). Although the
function sg_proc_write_dressz enforces this limit, it is possible to bypass
it by directly modifying the module parameter as shown below, which then
causes a soft lockup:
echo -1 > /sys/module/sg/parameters/def_reserved_size
exec 4<> /dev/sg0
watchdog: BUG: soft lockup - CPU#5 stuck for 26 seconds! [bash:537]
Modules loaded:
CPU: 5 UID: 0 PID: 537 Command: bash, kernel version 6.19.0-rc3+ #134,
PREEMPT disabled
Hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS version
1.16.1-2.fc37 dated 04/01/2014
...
Call Trace:
sg_build_reserve+0x5c/0xa0
sg_add_sfp+0x168/0x270
sg_open+0x16e/0x340
chrdev_open+0xbe/0x230
do_dentry_open+0x175/0x480
vfs_open+0x34/0xf0
do_open+0x265/0x3d0
path_openat+0x110/0x290
do_filp_open+0xc3/0x170
do_sys_openat2+0x71/0xe0
__x64_sys_openat+0x6d/0xa0
do_syscall_64+0x62/0x310
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The fix is to use module_param_cb to validate and reject invalid values
assigned to def_reserved_size.
Fixes: 6460e75a10 ("[SCSI] sg: fixes for large page_size")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260127062044.3034148-3-yangerkun@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Add a third parameter 'const struct io_comp_batch *' to the rq_end_io_fn
callback signature. This allows end_io handlers to access the completion
batch context when requests are completed via blk_mq_end_request_batch().
The io_comp_batch is passed from blk_mq_end_request_batch(), while NULL
is passed from __blk_mq_end_request() and blk_mq_put_rq_ref() which don't
have batch context.
This infrastructure change enables drivers to detect whether they're
being called from a batched completion path (like iopoll) and access
additional context stored in the io_comp_batch.
Update all rq_end_io_fn implementations:
- block/blk-mq.c: blk_end_sync_rq
- block/blk-flush.c: flush_end_io, mq_flush_data_end_io
- drivers/nvme/host/ioctl.c: nvme_uring_cmd_end_io
- drivers/nvme/host/core.c: nvme_keep_alive_end_io
- drivers/nvme/host/pci.c: abort_endio, nvme_del_queue_end, nvme_del_cq_end
- drivers/nvme/target/passthru.c: nvmet_passthru_req_done
- drivers/scsi/scsi_error.c: eh_lock_door_done
- drivers/scsi/sg.c: sg_rq_end_io
- drivers/scsi/st.c: st_scsi_execute_end
- drivers/target/target_core_pscsi.c: pscsi_req_done
- drivers/md/dm-rq.c: end_clone_request
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A race condition was found in sg_proc_debug_helper(). It was observed on
a system using an IBM LTO-9 SAS Tape Drive (ULTRIUM-TD9) and monitoring
/proc/scsi/sg/debug every second. A very large elapsed time would
sometimes appear. This is caused by two race conditions.
We reproduced the issue with an IBM ULTRIUM-HH9 tape drive on an x86_64
architecture. A patched kernel was built, and the race condition could
not be observed anymore after the application of this patch. A
reproducer C program utilising the scsi_debug module was also built by
Changhui Zhong and can be viewed here:
https://github.com/MichaelRabek/linux-tests/blob/master/drivers/scsi/sg/sg_race_trigger.c
The first race happens between the reading of hp->duration in
sg_proc_debug_helper() and request completion in sg_rq_end_io(). The
hp->duration member variable may hold either of two types of
information:
#1 - The start time of the request. This value is present while
the request is not yet finished.
#2 - The total execution time of the request (end_time - start_time).
If sg_proc_debug_helper() executes *after* the value of hp->duration was
changed from #1 to #2, but *before* srp->done is set to 1 in
sg_rq_end_io(), a fresh timestamp is taken in the else branch, and the
elapsed time (value type #2) is subtracted from a timestamp, which
cannot yield a valid elapsed time (which is a type #2 value as well).
To fix this issue, the value of hp->duration must change under the
protection of the sfp->rq_list_lock in sg_rq_end_io(). Since
sg_proc_debug_helper() takes this read lock, the change to srp->done and
srp->header.duration will happen atomically from the perspective of
sg_proc_debug_helper() and the race condition is thus eliminated.
The second race condition happens between sg_proc_debug_helper() and
sg_new_write(). Even though hp->duration is set to the current time
stamp in sg_add_request() under the write lock's protection, it gets
overwritten by a call to get_sg_io_hdr(), which calls copy_from_user()
to copy struct sg_io_hdr from userspace into kernel space. hp->duration
is set to the start time again in sg_common_write(). If
sg_proc_debug_helper() is called between these two calls, an arbitrary
value set by userspace (usually zero) is used to compute the elapsed
time.
To fix this issue, hp->duration must be set to the current timestamp
again after get_sg_io_hdr() returns successfully. A small race window
still exists between get_sg_io_hdr() and setting hp->duration, but this
window is only a few instructions wide and does not result in observable
issues in practice, as confirmed by testing.
Additionally, we fix the format specifier from %d to %u for printing
unsigned int values in sg_proc_debug_helper().
Signed-off-by: Michal Rábek <mrabek@redhat.com>
Suggested-by: Tomas Henzl <thenzl@redhat.com>
Tested-by: Changhui Zhong <czhong@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Link: https://patch.msgid.link/20251212160900.64924-1-mrabek@redhat.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Fix a use-after-free bug in sg_release(), detected by syzbot with KASAN:
BUG: KASAN: slab-use-after-free in lock_release+0x151/0xa30
kernel/locking/lockdep.c:5838
__mutex_unlock_slowpath+0xe2/0x750 kernel/locking/mutex.c:912
sg_release+0x1f4/0x2e0 drivers/scsi/sg.c:407
In sg_release(), the function kref_put(&sfp->f_ref, sg_remove_sfp) is
called before releasing the open_rel_lock mutex. The kref_put() call may
decrement the reference count of sfp to zero, triggering its cleanup
through sg_remove_sfp(). This cleanup includes scheduling deferred work
via sg_remove_sfp_usercontext(), which ultimately frees sfp.
After kref_put(), sg_release() continues to unlock open_rel_lock and may
reference sfp or sdp. If sfp has already been freed, this results in a
slab-use-after-free error.
Move the kref_put(&sfp->f_ref, sg_remove_sfp) call after unlocking the
open_rel_lock mutex. This ensures:
- No references to sfp or sdp occur after the reference count is
decremented.
- Cleanup functions such as sg_remove_sfp() and
sg_remove_sfp_usercontext() can safely execute without impacting the
mutex handling in sg_release().
The fix has been tested and validated by syzbot. This patch closes the
bug reported at the following syzkaller link and ensures proper
sequencing of resource cleanup and mutex operations, eliminating the
risk of use-after-free errors in sg_release().
Reported-by: syzbot+7efb5850a17ba6ce098b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7efb5850a17ba6ce098b
Tested-by: syzbot+7efb5850a17ba6ce098b@syzkaller.appspotmail.com
Fixes: cc833acbee ("sg: O_EXCL and other lock handling")
Signed-off-by: Suraj Sonawane <surajsonawane0215@gmail.com>
Link: https://lore.kernel.org/r/20241120125944.88095-1-surajsonawane0215@gmail.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In 2010, runtime power management support was implemented in the SCSI
core. The description of patch "[SCSI] implement runtime Power
Management" mentions that the sg driver is skipped but not why. This
patch enables runtime power management even if an instance of the sg
driver is held open. Enabling runtime PM for the sg driver is safe
because all interactions of the sg driver with the SCSI device pass
through the block layer (blk_execute_rq_nowait()) and the block layer
already supports runtime PM.
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Fixes: bc4f24014d ("[SCSI] implement runtime Power Management")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241030220310.1373569-1-bvanassche@acm.org
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove sentinel from scsi_table and sg_sysctls.
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Pull SCSI updates from James Bottomley:
"Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
lpfc, qla2xxx).
We have a couple of major core changes impacting other systems:
- Command Duration Limits, which spills into block and ATA
- block level Persistent Reservation Operations, which touches block,
nvme, target and dm
Both of these are added with merge commits containing a cover letter
explaining what's going on"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (187 commits)
scsi: core: Improve warning message in scsi_device_block()
scsi: core: Replace scsi_target_block() with scsi_block_targets()
scsi: core: Don't wait for quiesce in scsi_device_block()
scsi: core: Don't wait for quiesce in scsi_stop_queue()
scsi: core: Merge scsi_internal_device_block() and device_block()
scsi: sg: Increase number of devices
scsi: bsg: Increase number of devices
scsi: qla2xxx: Remove unused nvme_ls_waitq wait queue
scsi: ufs: ufs-pci: Add support for Intel Arrow Lake
scsi: sd: sd_zbc: Use PAGE_SECTORS_SHIFT
scsi: ufs: wb: Add explicit flush_threshold sysfs attribute
scsi: ufs: ufs-qcom: Switch to the new ICE API
scsi: ufs: dt-bindings: qcom: Add ICE phandle
scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_RTC quirk
scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_INTR quirk
scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_RTC
scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_INTR
scsi: ufs: core: Remove dedicated hwq for dev command
scsi: ufs: core: mcq: Fix the incorrect OCS value for the device command
scsi: ufs: dt-bindings: samsung,exynos: Drop unneeded quotes
...
In order to prevent request_queue to be freed before cleaning up
blktrace debugfs entries, commit db59133e92 ("scsi: sg: fix blktrace
debugfs entries leakage") use scsi_device_get(), however,
scsi_device_get() will also grab scsi module reference and scsi module
can't be removed.
It's reported that blktests can't unload scsi_debug after block/001:
blktests (master) # ./check block
block/001 (stress device hotplugging) [failed]
+++ /root/blktests/results/nodev/block/001.out.bad 2023-06-19
Running block/001
Stressing sd
+modprobe: FATAL: Module scsi_debug is in use.
Fix this problem by grabbing request_queue reference directly, so that
scsi host module can still be unloaded while request_queue will be
pinged by sg device.
Reported-by: Chaitanya Kulkarni <chaitanyak@nvidia.com>
Link: https://lore.kernel.org/all/1760da91-876d-fc9c-ab51-999a6f66ad50@nvidia.com/
Fixes: db59133e92 ("scsi: sg: fix blktrace debugfs entries leakage")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230621160111.1433521-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
sg_ioctl() support to enable blktrace, which will create debugfs entries
"/sys/kernel/debug/block/sgx/", however, there is no guarantee that user
will remove these entries through ioctl, and deleting sg device doesn't
cleanup these blktrace entries.
This problem can be fixed by cleanup blktrace while releasing
request_queue, however, it's not a good idea to do this special handling
in common layer just for sg device.
Fix this problem by shutdown bltkrace in sg_device_destroy(), where the
device is deleted and all the users close the device, also grab a
scsi_device reference from sg_add_device() to prevent scsi_device to be
freed before sg_device_destroy();
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20230610022003.2557284-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull more SCSI updates from James Bottomley:
"Mostly small bug fixes and small updates.
The only things of note is a qla2xxx fix for crash on hotplug and
timeout and the addition of a user exposed abstraction layer for
persistent reservation error return handling (which necessitates the
conversion of nvme.c as well as SCSI)"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: qla2xxx: Fix crash when I/O abort times out
nvme: Convert NVMe errors to PR errors
scsi: sd: Convert SCSI errors to PR errors
scsi: core: Rename status_byte to sg_status_byte
block: Add error codes for common PR failures
scsi: sd: sd_zbc: Trace zone append emulation
scsi: libfc: Include the correct header
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Everything is just converted to returning RQ_END_IO_NONE, and there
should be no functional changes with this patch.
In preparation for allowing the end_io handler to pass ownership back
to the block layer, rather than retain ownership of the request.
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When a SCSI device is removed while in active use, currently sg will
immediately return -ENODEV on any attempt to wait for active commands that
were sent before the removal. This is problematic for commands that use
SG_FLAG_DIRECT_IO since the data buffer may still be in use by the kernel
when userspace frees or reuses it after getting ENODEV, leading to
corrupted userspace memory (in the case of READ-type commands) or corrupted
data being sent to the device (in the case of WRITE-type commands). This
has been seen in practice when logging out of a iscsi_tcp session, where
the iSCSI driver may still be processing commands after the device has been
marked for removal.
Change the policy to allow userspace to wait for active sg commands even
when the device is being removed. Return -ENODEV only when there are no
more responses to read.
Link: https://lore.kernel.org/r/5ebea46f-fe83-2d0b-233d-d0dcb362dd0a@cybernetics.com
Cc: <stable@vger.kernel.org>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Now that each scsi_request is backed by a scsi_cmnd, there is no need to
indirect the CDB storage. Change all submitters of SCSI passthrough
requests to store the CDB information directly in the scsi_cmnd, and while
doing so allocate the full 32 bytes that cover all Linux supported SCSI
hosts instead of requiring dynamic allocation for > 16 byte CDBs. On
64-bit systems this does not change the size of the scsi_cmnd at all, while
on 32-bit systems it slightly increases it for now, but that increase will
be made up by the removal of the remaining scsi_request fields.
Link: https://lore.kernel.org/r/20220224175552.988286-4-hch@lst.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
There are no remaining callers of set_fs(), so CONFIG_SET_FS
can be removed globally, along with the thread_info field and
any references to it.
This turns access_ok() into a cheaper check against TASK_SIZE_MAX.
As CONFIG_SET_FS is now gone, drop all remaining references to
set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel().
Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes
Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic]
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Add a new helper that calls blk_get_request and initializes the
scsi_request to avoid the indirect call through ->.initialize_rq_fn.
Note that this makes the pktcdvd driver depend on the SCSI core, but
given that only SCSI devices support SCSI passthrough requests that
is not a functional change.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20211021060607.264371-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
