kernel.git/fs/f2fs/file.c, branch linux-6.10.y

f2fs: fix to check atomic_file in f2fs ioctl interfaces

2024-10-04T14:33:39Z

commit bfe5c02654261bfb8bd9cb174a67f3279ea99e58 upstream. Some f2fs ioctl interfaces like f2fs_ioc_set_pin_file(), f2fs_move_file_range(), and f2fs_defragment_range() missed to check atomic_write status, which may cause potential race issue, fix it. Cc: stable@vger.kernel.org Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: Require FMODE_WRITE for atomic write ioctls

2024-10-04T14:33:39Z

commit 4f5a100f87f32cb65d4bb1ad282a08c92f6f591e upstream. The F2FS ioctls for starting and committing atomic writes check for inode_owner_or_capable(), but this does not give LSMs like SELinux or Landlock an opportunity to deny the write access - if the caller's FSUID matches the inode's UID, inode_owner_or_capable() immediately returns true. There are scenarios where LSMs want to deny a process the ability to write particular files, even files that the FSUID of the process owns; but this can currently partially be bypassed using atomic write ioctls in two ways: - F2FS_IOC_START_ATOMIC_REPLACE + F2FS_IOC_COMMIT_ATOMIC_WRITE can truncate an inode to size 0 - F2FS_IOC_START_ATOMIC_WRITE + F2FS_IOC_ABORT_ATOMIC_WRITE can revert changes another process concurrently made to a file Fix it by requiring FMODE_WRITE for these operations, just like for F2FS_IOC_MOVE_RANGE. Since any legitimate caller should only be using these ioctls when intending to write into the file, that seems unlikely to break anything. Fixes: 88b88a667971 ("f2fs: support atomic writes") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Reviewed-by: Chao Yu Reviewed-by: Eric Biggers Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: fix several potential integer overflows in file offsets

2024-10-04T14:33:38Z

commit 1cade98cf6415897bf9342ee451cc5b40b58c638 upstream. When dealing with large extents and calculating file offsets by summing up according extent offsets and lengths of unsigned int type, one may encounter possible integer overflow if the values are big enough. Prevent this from happening by expanding one of the addends to (pgoff_t) type. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Fixes: d323d005ac4a ("f2fs: support file defragment") Cc: stable@vger.kernel.org Signed-off-by: Nikita Zhandarovich Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: compress: don't redirty sparse cluster during {,de}compress

2024-10-04T14:33:15Z

[ Upstream commit f785cec298c95d00058560c0715233294a04b8f3 ] In f2fs_do_write_data_page, when the data block is NULL_ADDR, it skips writepage considering that it has been already truncated. This results in an infinite loop as the PAGECACHE_TAG_TOWRITE tag is not cleared during the writeback process for a compressed file including NULL_ADDR in compress_mode=user. This is the reproduction process: 1. dd if=/dev/zero bs=4096 count=1024 seek=1024 of=testfile 2. f2fs_io compress testfile 3. dd if=/dev/zero bs=4096 count=1 conv=notrunc of=testfile 4. f2fs_io decompress testfile To prevent the problem, let's check whether the cluster is fully allocated before redirty its pages. Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") Reviewed-by: Sungjong Seo Reviewed-by: Sunmin Jeong Tested-by: Jaewook Kim Signed-off-by: Yeongjin Gil Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()

2024-10-04T14:33:15Z

[ Upstream commit c7f114d864ac91515bb07ac271e9824a20f5ed95 ] syzbot reports a f2fs bug as below: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:184 [inline] __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] get_task_struct include/linux/sched/task.h:118 [inline] kthread_stop+0xca/0x630 kernel/kthread.c:704 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210 f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283 f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline] __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 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 The root cause is below race condition, it may cause use-after-free issue in sbi->gc_th pointer. - remount - f2fs_remount - f2fs_stop_gc_thread - kfree(gc_th) - f2fs_ioc_shutdown - f2fs_do_shutdown - f2fs_stop_gc_thread - kthread_stop(gc_th->f2fs_gc_task) : sbi->gc_thread = NULL; We will call f2fs_do_shutdown() in two paths: - for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore for fixing. - for f2fs_shutdown() path, it's safe since caller has already grabbed sb->s_umount semaphore. Reported-by: syzbot+1a8e2b31f2ac9bd3d148@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/0000000000005c7ccb061e032b9b@google.com Fixes: 7950e9ac638e ("f2fs: stop gc/discard thread after fs shutdown") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: atomic: fix to truncate pagecache before on-disk metadata truncation

2024-10-04T14:33:15Z

[ Upstream commit ebd3309aec6271c4616573b0cb83ea25e623070a ] We should always truncate pagecache while truncating on-disk data. Fixes: a46bebd502fe ("f2fs: synchronize atomic write aborts") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to wait page writeback before setting gcing flag

2024-10-04T14:33:15Z

[ Upstream commit a4d7f2b3238fd5f76b9e6434a0bd5d2e29049cff ] Soft IRQ Thread - f2fs_write_end_io - f2fs_defragment_range - set_page_private_gcing - type = WB_DATA_TYPE(page, false); : assign type w/ F2FS_WB_CP_DATA due to page_private_gcing() is true - dec_page_count() w/ wrong type - end_page_writeback() Value of F2FS_WB_CP_DATA reference count may become negative under above race condition, the root cause is we missed to wait page writeback before setting gcing page private flag, let's fix it. Fixes: 2d1fe8a86bf5 ("f2fs: fix to tag gcing flag on page during file defragment") Fixes: 4961acdd65c9 ("f2fs: fix to tag gcing flag on page during block migration") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: Create COW inode from parent dentry for atomic write

2024-10-04T14:33:14Z

[ Upstream commit 8c1b787938fd86bab27a1492fa887408c75fec2b ] The i_pino in f2fs_inode_info has the previous parent's i_ino when inode was renamed, which may cause f2fs_ioc_start_atomic_write to fail. If file_wrong_pino is true and i_nlink is 1, then to find a valid pino, we should refer to the dentry from inode. To resolve this issue, let's get parent inode using parent dentry directly. Fixes: 3db1de0e582c ("f2fs: change the current atomic write way") Reviewed-by: Sungjong Seo Reviewed-by: Sunmin Jeong Signed-off-by: Yeongjin Gil Reviewed-by: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: fix to avoid racing in between read and OPU dio write

2024-10-04T14:33:14Z

[ Upstream commit 0cac51185e65dc2a20686184e02f3cafc99eb202 ] If lfs mode is on, buffered read may race w/ OPU dio write as below, it may cause buffered read hits unwritten data unexpectly, and for dio read, the race condition exists as well. Thread A Thread B - f2fs_file_write_iter - f2fs_dio_write_iter - __iomap_dio_rw - f2fs_iomap_begin - f2fs_map_blocks - __allocate_data_block - allocated blkaddr #x - iomap_dio_submit_bio - f2fs_file_read_iter - filemap_read - f2fs_read_data_folio - f2fs_mpage_readpages - f2fs_map_blocks : get blkaddr #x - f2fs_submit_read_bio IRQ - f2fs_read_end_io : read IO on blkaddr #x complete IRQ - iomap_dio_bio_end_io : direct write IO on blkaddr #x complete In LFS mode, if there is inflight dio, let's wait for its completion, this policy won't cover all race cases, however it is a tradeoff which avoids abusing lock around IO paths. Fixes: f847c699cff3 ("f2fs: allow out-place-update for direct IO in LFS mode") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: reduce expensive checkpoint trigger frequency

2024-10-04T14:33:14Z

[ Upstream commit aaf8c0b9ae042494cb4585883b15c1332de77840 ] We may trigger high frequent checkpoint for below case: 1. mkdir /mnt/dir1; set dir1 encrypted 2. touch /mnt/file1; fsync /mnt/file1 3. mkdir /mnt/dir2; set dir2 encrypted 4. touch /mnt/file2; fsync /mnt/file2 ... Although, newly created dir and file are not related, due to commit bbf156f7afa7 ("f2fs: fix lost xattrs of directories"), we will trigger checkpoint whenever fsync() comes after a new encrypted dir created. In order to avoid such performance regression issue, let's record an entry including directory's ino in global cache whenever we update directory's xattr data, and then triggerring checkpoint() only if xattr metadata of target file's parent was updated. This patch updates to cover below no encryption case as well: 1) parent is checkpointed 2) set_xattr(dir) w/ new xnid 3) create(file) 4) fsync(file) Fixes: bbf156f7afa7 ("f2fs: fix lost xattrs of directories") Reported-by: wangzijie Reported-by: Zhiguo Niu Tested-by: Zhiguo Niu Reported-by: Yunlei He Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin