kernel/linux.git/fs/udf, branch v5.15.208

fs: udf: fix OOB read in lengthAllocDescs handling

2025-10-19T14:21:38+00:00

commit 3bd5e45c2ce30e239d596becd5db720f7eb83c99 upstream. 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: Greg Kroah-Hartman

udf: Fix directory iteration for longer tail extents

2025-09-04T12:28:44+00:00

commit 1ea1cd11c72d1405a6b98440a9d5ea82dfa07166 upstream. When directory's last extent has more that one block and its length is not multiple of a block side, the code wrongly decided to move to the next extent instead of processing the last partial block. This led to directory corruption. Fix the rounding issue. Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

udf: Verify partition map count

2025-08-28T14:24:16+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: Avoid directory type conversion failure due to ENOMEM

2024-11-17T14:06:26+00:00

commit df97f64dfa317a5485daf247b6c043a584ef95f9 upstream. When converting directory from in-ICB to normal format, the last iteration through the directory fixing up directory enteries can fail due to ENOMEM. We do not expect this iteration to fail since the directory is already verified to be correct and it is difficult to undo the conversion at this point. So just use GFP_NOFAIL to make sure the small allocation cannot fail. Reported-by: syzbot+111eaa994ff74f8d440f@syzkaller.appspotmail.com Fixes: 0aba4860b0d0 ("udf: Allocate name buffer in directory iterator on heap") Signed-off-by: Jan Kara Signed-off-by: Hauke Mehrtens Signed-off-by: Greg Kroah-Hartman

udf: Allocate name buffer in directory iterator on heap

2024-11-17T14:06:26+00:00

commit 0aba4860b0d0216a1a300484ff536171894d49d8 upstream. Currently we allocate name buffer in directory iterators (struct udf_fileident_iter) on stack. These structures are relatively large (some 360 bytes on 64-bit architectures). For udf_rename() which needs to keep three of these structures in parallel the stack usage becomes rather heavy - 1536 bytes in total. Allocate the name buffer in the iterator from heap to avoid excessive stack usage. Link: https://lore.kernel.org/all/202212200558.lK9x1KW0-lkp@intel.com Reported-by: kernel test robot Signed-off-by: Jan Kara [Add extra include linux/slab.h] Signed-off-by: Hauke Mehrtens Signed-off-by: Greg Kroah-Hartman

udf: fix uninit-value use in udf_get_fileshortad

2024-11-01T00:52:35+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 Signed-off-by: Sasha Levin

udf: Fix bogus checksum computation in udf_rename()

2024-10-22T13:40:39+00:00

[ Upstream commit 27ab33854873e6fb958cb074681a0107cc2ecc4c ] Syzbot reports uninitialized memory access in udf_rename() when updating checksum of '..' directory entry of a moved directory. This is indeed true as we pass on-stack diriter.fi to the udf_update_tag() and because that has only struct fileIdentDesc included in it and not the impUse or name fields, the checksumming function is going to checksum random stack contents beyond the end of the structure. This is actually harmless because the following udf_fiiter_write_fi() will recompute the checksum from on-disk buffers where everything is properly included. So all that is needed is just removing the bogus calculation. Fixes: e9109a92d2a9 ("udf: Convert udf_rename() to new directory iteration code") Link: https://lore.kernel.org/all/000000000000cf405f060d8f75a9@google.com/T/ Link: https://patch.msgid.link/20240617154201.29512-1-jack@suse.cz Reported-by: syzbot+d31185aa54170f7fc1f5@syzkaller.appspotmail.com Signed-off-by: Jan Kara Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

udf: Don't return bh from udf_expand_dir_adinicb()

2024-10-22T13:40:39+00:00

[ Upstream commit f386c802a6fda8f9fe4a5cf418c49aa84dfc52e4 ] Nobody uses the bh returned from udf_expand_dir_adinicb(). Don't return it. Signed-off-by: Jan Kara [cascardo: skip backport of 101ee137d32a ("udf: Drop VARCONV support")] Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

udf: Handle error when expanding directory

2024-10-22T13:40:39+00:00

[ Upstream commit 33e9a53cd9f099b138578f8e1a3d60775ff8cbba ] When there is an error when adding extent to the directory to expand it, make sure to propagate the error up properly. This is not expected to happen currently but let's make the code more futureproof. Signed-off-by: Jan Kara Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

udf: Remove old directory iteration code

2024-10-22T13:40:39+00:00

[ Upstream commit 1e0290d61a870ed61a6510863029939bbf6b0006 ] Remove old directory iteration code that is now unused. Signed-off-by: Jan Kara Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman