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b4cc4a4077
The check for a fast symlink in the presence of only an
external xattr inode is incorrect. If a fast symlink does
not have an xattr block (i_file_acl == 0), but does have
an external xattr inode that increases inode i_blocks, then
the check for a fast symlink will incorrectly fail and
__ext4_iget()->ext4_ind_check_inode() will report the inode
is corrupt when it "validates" i_data[] on the next read:
# ln -s foo /mnt/tmp/bar
# setfattr -h -n trusted.test \
-v "$(yes | head -n 4000)" /mnt/tmp/bar
# umount /mnt/tmp
# mount /mnt/tmp
# ls -l /mnt/tmp
ls: cannot access '/mnt/tmp/bar': Structure needs cleaning
total 4
? l?????????? ? ? ? ? ? bar
# dmesg | tail -1
EXT4-fs error (device dm-8): __ext4_iget:5098:
inode #24578: block 7303014: comm ls: invalid block
(note that "block 7303014" = 0x6f6f66 = "foo" in LE order).
ext4_inode_is_fast_symlink() should check the superblock
EXT4_FEATURE_INCOMPAT_EA_INODE feature flag, not the inode
EXT4_EA_INODE_FL, since the latter is only set on the xattr
inode itself, and not on the inode that uses this xattr.
Cc: stable@vger.kernel.org
Fixes: fc82228a5e ("ext4: support fast symlinks from ext3 file systems")
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/59879
Lustre-bug-id: https://jira.whamcloud.com/browse/LU-19121
Link: https://patch.msgid.link/20250717063709.757077-1-adilger@dilger.ca
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.