This is a note to let you know that I've just added the patch titled f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: f2fs-fix-null-ptr-deref-in-f2fs_get_dnode_of_data.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4a2c5b7994960fac29cf8a3f4e62855bae1b27d4 Mon Sep 17 00:00:00 2001 From: Ye Bin <yebin10@xxxxxxxxxx> Date: Mon, 1 Aug 2022 19:26:04 +0800 Subject: f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data From: Ye Bin <yebin10@xxxxxxxxxx> commit 4a2c5b7994960fac29cf8a3f4e62855bae1b27d4 upstream. There is issue as follows when test f2fs atomic write: F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop0): invalid crc_offset: 0 F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=1, run fsck to fix. F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=2, run fsck to fix. ================================================================== BUG: KASAN: null-ptr-deref in f2fs_get_dnode_of_data+0xac/0x16d0 Read of size 8 at addr 0000000000000028 by task rep/1990 CPU: 4 PID: 1990 Comm: rep Not tainted 5.19.0-rc6-next-20220715 #266 Call Trace: <TASK> dump_stack_lvl+0x6e/0x91 print_report.cold+0x49a/0x6bb kasan_report+0xa8/0x130 f2fs_get_dnode_of_data+0xac/0x16d0 f2fs_do_write_data_page+0x2a5/0x1030 move_data_page+0x3c5/0xdf0 do_garbage_collect+0x2015/0x36c0 f2fs_gc+0x554/0x1d30 f2fs_balance_fs+0x7f5/0xda0 f2fs_write_single_data_page+0xb66/0xdc0 f2fs_write_cache_pages+0x716/0x1420 f2fs_write_data_pages+0x84f/0x9a0 do_writepages+0x130/0x3a0 filemap_fdatawrite_wbc+0x87/0xa0 file_write_and_wait_range+0x157/0x1c0 f2fs_do_sync_file+0x206/0x12d0 f2fs_sync_file+0x99/0xc0 vfs_fsync_range+0x75/0x140 f2fs_file_write_iter+0xd7b/0x1850 vfs_write+0x645/0x780 ksys_write+0xf1/0x1e0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd As 3db1de0e582c commit changed atomic write way which new a cow_inode for atomic write file, and also mark cow_inode as FI_ATOMIC_FILE. When f2fs_do_write_data_page write cow_inode will use cow_inode's cow_inode which is NULL. Then will trigger null-ptr-deref. To solve above issue, introduce FI_COW_FILE flag for COW inode. Fiexes: 3db1de0e582c("f2fs: change the current atomic write way") Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> Reviewed-by: Chao Yu <chao@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/f2fs/f2fs.h | 6 ++++++ fs/f2fs/file.c | 2 +- fs/f2fs/segment.c | 4 ++-- 3 files changed, 9 insertions(+), 3 deletions(-) --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -756,6 +756,7 @@ enum { FI_ENABLE_COMPRESS, /* enable compression in "user" compression mode */ FI_COMPRESS_RELEASED, /* compressed blocks were released */ FI_ALIGNED_WRITE, /* enable aligned write */ + FI_COW_FILE, /* indicate COW file */ FI_MAX, /* max flag, never be used */ }; @@ -3188,6 +3189,11 @@ static inline bool f2fs_is_atomic_file(s return is_inode_flag_set(inode, FI_ATOMIC_FILE); } +static inline bool f2fs_is_cow_file(struct inode *inode) +{ + return is_inode_flag_set(inode, FI_COW_FILE); +} + static inline bool f2fs_is_first_block_written(struct inode *inode) { return is_inode_flag_set(inode, FI_FIRST_BLOCK_WRITTEN); --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2055,7 +2055,7 @@ static int f2fs_ioc_start_atomic_write(s spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); set_inode_flag(inode, FI_ATOMIC_FILE); - set_inode_flag(fi->cow_inode, FI_ATOMIC_FILE); + set_inode_flag(fi->cow_inode, FI_COW_FILE); clear_inode_flag(fi->cow_inode, FI_INLINE_DATA); f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -193,7 +193,7 @@ void f2fs_abort_atomic_write(struct inod if (f2fs_is_atomic_file(inode)) { if (clean) truncate_inode_pages_final(inode->i_mapping); - clear_inode_flag(fi->cow_inode, FI_ATOMIC_FILE); + clear_inode_flag(fi->cow_inode, FI_COW_FILE); iput(fi->cow_inode); fi->cow_inode = NULL; clear_inode_flag(inode, FI_ATOMIC_FILE); @@ -3167,7 +3167,7 @@ static int __get_segment_type_6(struct f return CURSEG_COLD_DATA; if (file_is_hot(inode) || is_inode_flag_set(inode, FI_HOT_DATA) || - f2fs_is_atomic_file(inode)) + f2fs_is_cow_file(inode)) return CURSEG_HOT_DATA; return f2fs_rw_hint_to_seg_type(inode->i_write_hint); } else { Patches currently in stable-queue which might be from yebin10@xxxxxxxxxx are queue-5.18/f2fs-fix-null-ptr-deref-in-f2fs_get_dnode_of_data.patch queue-5.18/ext4-fix-warning-in-ext4_iomap_begin-as-race-between.patch queue-5.18/ext4-fix-extent-status-tree-race-in-writeback-error-.patch