kernel/linux.git/fs/fat, branch v5.10.257

fat: avoid parent link count underflow in rmdir

2026-03-04T12:19:34+00:00

[ Upstream commit 8cafcb881364af5ef3a8b9fed4db254054033d8a ] Corrupted FAT images can leave a directory inode with an incorrect i_nlink (e.g. 2 even though subdirectories exist). rmdir then unconditionally calls drop_nlink(dir) and can drive i_nlink to 0, triggering the WARN_ON in drop_nlink(). Add a sanity check in vfat_rmdir() and msdos_rmdir(): only drop the parent link count when it is at least 3, otherwise report a filesystem error. Link: https://lkml.kernel.org/r/20260101111148.1437-1-zhiyuzhang999@gmail.com Fixes: 9a53c3a783c2 ("[PATCH] r/o bind mounts: unlink: monitor i_nlink") Signed-off-by: Zhiyu Zhang Reported-by: Zhiyu Zhang Closes: https://lore.kernel.org/linux-fsdevel/aVN06OKsKxZe6-Kv@casper.infradead.org/T/#t Tested-by: Zhiyu Zhang Acked-by: OGAWA Hirofumi Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

fat: fix uninitialized variable

2024-10-22T13:39:24+00:00

commit 963a7f4d3b90ee195b895ca06b95757fcba02d1a upstream. syszbot produced this with a corrupted fs image. In theory, however an IO error would trigger this also. This affects just an error report, so should not be a serious error. Link: https://lkml.kernel.org/r/87r08wjsnh.fsf@mail.parknet.co.jp Link: https://lkml.kernel.org/r/66ff2c95.050a0220.49194.03e9.GAE@google.com Signed-off-by: OGAWA Hirofumi Reported-by: syzbot+ef0d7bc412553291aa86@syzkaller.appspotmail.com Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

fat: fix uninitialized field in nostale filehandles

2024-04-13T10:58:08+00:00

[ Upstream commit fde2497d2bc3a063d8af88b258dbadc86bd7b57c ] When fat_encode_fh_nostale() encodes file handle without a parent it stores only first 10 bytes of the file handle. However the length of the file handle must be a multiple of 4 so the file handle is actually 12 bytes long and the last two bytes remain uninitialized. This is not great at we potentially leak uninitialized information with the handle to userspace. Properly initialize the full handle length. Link: https://lkml.kernel.org/r/20240205122626.13701-1-jack@suse.cz Reported-by: syzbot+3ce5dea5b1539ff36769@syzkaller.appspotmail.com Fixes: ea3983ace6b7 ("fat: restructure export_operations") Signed-off-by: Jan Kara Acked-by: OGAWA Hirofumi Cc: Amir Goldstein Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

fat: add ratelimit to fat*_ent_bread()

2022-06-09T08:20:58+00:00

[ Upstream commit 183c3237c928109d2008c0456dff508baf692b20 ] fat*_ent_bread() can be the cause of too many report on I/O error path. So use fat_msg_ratelimit() instead. Link: https://lkml.kernel.org/r/87bkxogfeq.fsf@mail.parknet.co.jp Signed-off-by: OGAWA Hirofumi Reported-by: qianfan Tested-by: qianfan Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

[PATCH] reduce boilerplate in fsid handling

2020-09-18T20:45:50+00:00

Get rid of boilerplate in most of ->statfs() instances... Signed-off-by: Al Viro

fat: fix fat_ra_init() for data clusters == 0

2020-08-12T17:58:01+00:00

If data clusters == 0, fat_ra_init() calls the ->ent_blocknr() for the cluster beyond ->max_clusters. This checks the limit before initialization to suppress the warning. Reported-by: syzbot+756199124937b31a9b7e@syzkaller.appspotmail.com Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/87mu462sv4.fsf@mail.parknet.co.jp Signed-off-by: Linus Torvalds

VFAT/FAT/MSDOS FILESYSTEM: replace HTTP links with HTTPS ones

2020-08-12T17:58:01+00:00

Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `xmlns`: For each link, `http://[^# ]*(?:\w|/)`: If neither `gnu\.org/license`, nor `mozilla\.org/MPL`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov Signed-off-by: Andrew Morton Acked-by: OGAWA Hirofumi Link: http://lkml.kernel.org/r/20200708200409.22293-1-grandmaster@al2klimov.de Signed-off-by: Linus Torvalds

fatfs: switch write_lock to read_lock in fat_ioctl_get_attributes

2020-08-12T17:58:01+00:00

There is no need to hold write_lock in fat_ioctl_get_attributes. write_lock may make an impact on concurrency of fat_ioctl_get_attributes. Signed-off-by: Yubo Feng Signed-off-by: Andrew Morton Acked-by: OGAWA Hirofumi Link: http://lkml.kernel.org/r/1593308053-12702-1-git-send-email-fengyubo3@huawei.com Signed-off-by: Linus Torvalds

treewide: Remove uninitialized_var() usage

2020-07-16T19:35:15+00:00

Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var$([^$]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook

fat: improve the readahead for FAT entries

2020-06-05T02:06:25+00:00

Current readahead for FAT entries is very simple but is having some flaws, so it is not working well for some environments. This patch improves the readahead more or less. The key points of modification are, - make the readahead size tunable by using bdi->ra_pages - care the bdi->io_pages to avoid the small size I/O request - update readahead window before fully exhausting With this patch, on slow USB connected 2TB hdd: [before] 383.18sec [after] 51.03sec Signed-off-by: OGAWA Hirofumi Signed-off-by: Andrew Morton Tested-by: hyeongseok.kim Reviewed-by: hyeongseok.kim Link: http://lkml.kernel.org/r/87d08e1dlh.fsf@mail.parknet.co.jp Signed-off-by: Linus Torvalds