[ Upstream commit 05573d6ccf702df549a7bdeabef31e4753df1a90 ] As Jungyeon reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203239 - Overview When mounting the attached crafted image and running program, following errors are reported. Additionally, it hangs on sync after running program. The image is intentionally fuzzed from a normal f2fs image for testing. Compile options for F2FS are as follows. CONFIG_F2FS_FS=y CONFIG_F2FS_STAT_FS=y CONFIG_F2FS_FS_XATTR=y CONFIG_F2FS_FS_POSIX_ACL=y CONFIG_F2FS_CHECK_FS=y - Reproduces cc poc_15.c ./run.sh f2fs sync - Kernel messages ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:3162! RIP: 0010:f2fs_inplace_write_data+0x12d/0x160 Call Trace: f2fs_do_write_data_page+0x3c1/0x820 __write_data_page+0x156/0x720 f2fs_write_cache_pages+0x20d/0x460 f2fs_write_data_pages+0x1b4/0x300 do_writepages+0x15/0x60 __filemap_fdatawrite_range+0x7c/0xb0 file_write_and_wait_range+0x2c/0x80 f2fs_do_sync_file+0x102/0x810 do_fsync+0x33/0x60 __x64_sys_fsync+0xb/0x10 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The reason is f2fs_inplace_write_data() will trigger kernel panic due to data block locates in node type segment. To avoid panic, let's just return error code and set SBI_NEED_FSCK to give a hint to fsck for latter repairing. Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/segment.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 03fa2c4d3d79..8fc3edb6760c 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -3069,13 +3069,18 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio) { int err; struct f2fs_sb_info *sbi = fio->sbi; + unsigned int segno; fio->new_blkaddr = fio->old_blkaddr; /* i/o temperature is needed for passing down write hints */ __get_segment_type(fio); - f2fs_bug_on(sbi, !IS_DATASEG(get_seg_entry(sbi, - GET_SEGNO(sbi, fio->new_blkaddr))->type)); + segno = GET_SEGNO(sbi, fio->new_blkaddr); + + if (!IS_DATASEG(get_seg_entry(sbi, segno)->type)) { + set_sbi_flag(sbi, SBI_NEED_FSCK); + return -EFAULT; + } stat_inc_inplace_blocks(fio->sbi); -- 2.20.1
