kernel/linux.git/fs/udf/inode.c, branch v6.12.91

fs: udf: fix OOB read in lengthAllocDescs handling

2025-10-15T10:00:21+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 inode_getblk() return value

2025-04-20T08:15:43+00:00

commit 6afdc60ec30b0a9390d11b7cebed79c857ce82aa upstream. Smatch noticed that inode_getblk() can return 1 on successful mapping of a block instead of expected 0 after commit b405c1e58b73 ("udf: refactor udf_next_aext() to handle error"). This could confuse some of the callers and lead to strange failures (although the one reported by Smatch in udf_mkdir() is impossible to trigger in practice). Fix the return value of inode_getblk(). Link: https://lore.kernel.org/all/cb514af7-bbe0-435b-934f-dd1d7a16d2cd@stanley.mountain Reported-by: Dan Carpenter Reviewed-by: Carlos Maiolino Fixes: b405c1e58b73 ("udf: refactor udf_next_aext() to handle error") CC: stable@vger.kernel.org Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

udf: fix uninit-value use in udf_get_fileshortad

2024-10-02T12:32:37+00:00

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

udf: refactor inode_bmap() to handle error

2024-10-02T12:32:29+00:00

Refactor inode_bmap() to handle error since udf_next_aext() can return error now. On situations like ftruncate, udf_extend_file() can now detect errors and bail out early without resorting to checking for particular offsets and assuming internal behavior of these functions. Reported-by: syzbot+7a4842f0b1801230a989@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7a4842f0b1801230a989 Tested-by: syzbot+7a4842f0b1801230a989@syzkaller.appspotmail.com Signed-off-by: Zhao Mengmeng Suggested-by: Jan Kara Signed-off-by: Jan Kara Link: https://patch.msgid.link/20241001115425.266556-4-zhaomzhao@126.com

udf: refactor udf_next_aext() to handle error

2024-10-02T12:10:50+00:00

Since udf_current_aext() has error handling, udf_next_aext() should have error handling too. Besides, when too many indirect extents found in one inode, return -EFSCORRUPTED; when reading block failed, return -EIO. Signed-off-by: Zhao Mengmeng Suggested-by: Jan Kara Signed-off-by: Jan Kara Link: https://patch.msgid.link/20241001115425.266556-3-zhaomzhao@126.com

udf: refactor udf_current_aext() to handle error

2024-10-02T10:37:01+00:00

As Jan suggested in links below, refactor udf_current_aext() to differentiate between error, hit EOF and success, it now takes pointer to etype to store the extent type, return 1 when getting etype success, return 0 when hitting EOF and return -errno when err. Link: https://lore.kernel.org/all/20240912111235.6nr3wuqvktecy3vh@quack3/ Signed-off-by: Zhao Mengmeng Suggested-by: Jan Kara Signed-off-by: Jan Kara Link: https://patch.msgid.link/20241001115425.266556-2-zhaomzhao@126.com

fs: Convert aops->write_begin to take a folio

2024-08-07T09:33:21+00:00

Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

fs: Convert aops->write_end to take a folio

2024-08-07T09:32:02+00:00

Most callers have a folio, and most implementations operate on a folio, so remove the conversion from folio->page->folio to fit through this interface. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

udf: Fix lock ordering in udf_evict_inode()

2024-06-05T08:36:46+00:00

udf_evict_inode() calls udf_setsize() to truncate deleted inode. However inode deletion through udf_evict_inode() can happen from inode reclaim context and udf_setsize() grabs mapping->invalidate_lock which isn't generally safe to acquire from fs reclaim context since we allocate pages under mapping->invalidate_lock for example in a page fault path. This is however not a real deadlock possibility as by the time udf_evict_inode() is called, nobody can be accessing the inode, even less work with its page cache. So this is just a lockdep triggering false positive. Fix the problem by moving mapping->invalidate_lock locking outsize of udf_setsize() into udf_setattr() as grabbing mapping->invalidate_lock from udf_evict_inode() is pointless. Reported-by: syzbot+0333a6f4b88bcd68a62f@syzkaller.appspotmail.com Fixes: b9a861fd527a ("udf: Protect truncate and file type conversion with invalidate_lock") Signed-off-by: Jan Kara

udf: Drop pointless IS_IMMUTABLE and IS_APPEND check

2024-06-05T08:36:46+00:00

udf_setsize() checks for IS_IMMUTABLE and IS_APPEND flags. This is however pointless as UDF does not have capability to store these flags and never allows to set them. Furthermore this is the only place in UDF code that was actually checking these flags. Remove the pointless check. Signed-off-by: Jan Kara