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

fs: udf: fix OOB read in lengthAllocDescs handling

2025-10-29T13:01:14+00:00

[ Upstream commit 3bd5e45c2ce30e239d596becd5db720f7eb83c99 ] When parsing Allocation Extent Descriptor, lengthAllocDescs comes from on-disk data and must be validated against the block size. Crafted or corrupted images may set lengthAllocDescs so that the total descriptor length (sizeof(allocExtDesc) + lengthAllocDescs) exceeds the buffer, leading udf_update_tag() to call crc_itu_t() on out-of-bounds memory and trigger a KASAN use-after-free read. BUG: KASAN: use-after-free in crc_itu_t+0x1d5/0x2b0 lib/crc-itu-t.c:60 Read of size 1 at addr ffff888041e7d000 by task syz-executor317/5309 CPU: 0 UID: 0 PID: 5309 Comm: syz-executor317 Not tainted 6.12.0-rc4-syzkaller-00261-g850925a8133c #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 crc_itu_t+0x1d5/0x2b0 lib/crc-itu-t.c:60 udf_update_tag+0x70/0x6a0 fs/udf/misc.c:261 udf_write_aext+0x4d8/0x7b0 fs/udf/inode.c:2179 extent_trunc+0x2f7/0x4a0 fs/udf/truncate.c:46 udf_truncate_tail_extent+0x527/0x7e0 fs/udf/truncate.c:106 udf_release_file+0xc1/0x120 fs/udf/file.c:185 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 __do_sys_exit_group kernel/exit.c:1099 [inline] __se_sys_exit_group kernel/exit.c:1097 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Validate the computed total length against epos->bh->b_size. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Reported-by: syzbot+8743fca924afed42f93e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8743fca924afed42f93e Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Larshin Sergey Link: https://patch.msgid.link/20250922131358.745579-1-Sergey.Larshin@kaspersky.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

udf: fix uninit-value use in udf_get_fileshortad

2025-10-29T13:01:14+00:00

[ Upstream commit 264db9d666ad9a35075cc9ed9ec09d021580fbb1 ] Check for overflow when computing alen in udf_current_aext to mitigate later uninit-value use in udf_get_fileshortad KMSAN bug[1]. After applying the patch reproducer did not trigger any issue[2]. [1] https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df [2] https://syzkaller.appspot.com/x/log.txt?x=10242227980000 Reported-by: syzbot+8901c4560b7ab5c2f9df@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8901c4560b7ab5c2f9df Tested-by: syzbot+8901c4560b7ab5c2f9df@syzkaller.appspotmail.com Suggested-by: Jan Kara Signed-off-by: Gianfranco Trad Signed-off-by: Jan Kara Link: https://patch.msgid.link/20240925074613.8475-3-gianf.trad@gmail.com Stable-dep-of: 3bd5e45c2ce3 ("fs: udf: fix OOB read in lengthAllocDescs handling") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

udf: Verify partition map count

2025-08-28T14:22:39+00:00

[ Upstream commit 1a11201668e8635602577dcf06f2e96c591d8819 ] Verify that number of partition maps isn't insanely high which can lead to large allocation in udf_sb_alloc_partition_maps(). All partition maps have to fit in the LVD which is in a single block. Reported-by: syzbot+478f2c1a6f0f447a46bb@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Fix use of check_add_overflow() with mixed type arguments

2025-03-13T11:47:45+00:00

Commit ebbe26fd54a9 "udf: Avoid excessive partition lengths" introduced a use of check_add_overflow() with argument types u32, size_t, and u32 *. This was backported to the 5.x stable branches, where in 64-bit configurations it results in a build error (with older compilers) or a warning. Before commit d219d2a9a92e "overflow: Allow mixed type arguments", which went into Linux 6.1, mixed type arguments are not supported. That cannot be backported to 5.4 or 5.10 as it would raise the minimum compiler version for these kernel versions. Add a cast to make the argument types compatible. Fixes: 1497a4484cdb ("udf: Avoid excessive partition lengths") Fixes: 551966371e17 ("udf: Avoid excessive partition lengths") Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

udf: Avoid excessive partition lengths

2024-09-12T09:06:46+00:00

[ Upstream commit ebbe26fd54a9621994bc16b14f2ba8f84c089693 ] Avoid mounting filesystems where the partition would overflow the 32-bits used for block number. Also refuse to mount filesystems where the partition length is so large we cannot safely index bits in a block bitmap. Link: https://patch.msgid.link/20240620130403.14731-1-jack@suse.cz Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Limit file size to 4TB

2024-09-12T09:06:42+00:00

commit c2efd13a2ed4f29bf9ef14ac2fbb7474084655f8 upstream. UDF disk format supports in principle file sizes up to 1<<64-1. However the file space (including holes) is described by a linked list of extents, each of which can have at most 1GB. Thus the creation and handling of extents gets unusably slow beyond certain point. Limit the file size to 4TB to avoid locking up the kernel too easily. Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

udf: prevent integer overflow in udf_bitmap_free_blocks()

2024-08-19T03:41:13+00:00

[ Upstream commit 56e69e59751d20993f243fb7dd6991c4e522424c ] An overflow may occur if the function is called with the last block and an offset greater than zero. It is necessary to add a check to avoid this. Found by Linux Verification Center (linuxtesting.org) with Svace. [JK: Make test cover also unalloc table freeing] Link: https://patch.msgid.link/20240620072413.7448-1-r.smirnov@omp.ru Suggested-by: Jan Kara Signed-off-by: Roman Smirnov Signed-off-by: Jan Kara Signed-off-by: Sasha Levin

udf: Avoid using corrupted block bitmap buffer

2024-08-19T03:40:57+00:00

commit a90d4471146de21745980cba51ce88e7926bcc4f upstream. When the filesystem block bitmap is corrupted, we detect the corruption while loading the bitmap and fail the allocation with error. However the next allocation from the same bitmap will notice the bitmap buffer is already loaded and tries to allocate from the bitmap with mixed results (depending on the exact nature of the bitmap corruption). Fix the problem by using BH_verified bit to indicate whether the bitmap is valid or not. Reported-by: syzbot+5f682cd029581f9edfd1@syzkaller.appspotmail.com CC: stable@vger.kernel.org Link: https://patch.msgid.link/20240617154201.29512-2-jack@suse.cz Fixes: 1e0d4adf17e7 ("udf: Check consistency of Space Bitmap Descriptor") Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

udf: udftime: prevent overflow in udf_disk_stamp_to_time()

2024-07-05T07:12:36+00:00

[ Upstream commit 3b84adf460381169c085e4bc09e7b57e9e16db0a ] An overflow can occur in a situation where src.centiseconds takes the value of 255. This situation is unlikely, but there is no validation check anywere in the code. Found by Linux Verification Center (linuxtesting.org) with Svace. Suggested-by: Jan Kara Signed-off-by: Roman Smirnov Reviewed-by: Sergey Shtylyov Signed-off-by: Jan Kara Message-Id: <20240327132755.13945-1-r.smirnov@omp.ru> Signed-off-by: Sasha Levin

fs: add file and path permissions helpers

2024-06-21T12:52:58+00:00

[ Upstream commit 02f92b3868a1b34ab98464e76b0e4e060474ba10 ] Add two simple helpers to check permissions on a file and path respectively and convert over some callers. It simplifies quite a few codepaths and also reduces the churn in later patches quite a bit. Christoph also correctly points out that this makes codepaths (e.g. ioctls) way easier to follow that would otherwise have to do more complex argument passing than necessary. Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin