From: Chao Yu <yuchao0@xxxxxxxxxx> [ Upstream commit c854f4d681365498f53ba07843a16423625aa7e9 ] As Jungyeon Reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203233 - Reproduces gcc poc_13.c ./run.sh f2fs - Kernel messages F2FS-fs (sdb): Bitmap was wrongly set, blk:4608 kernel BUG at fs/f2fs/segment.c:2133! RIP: 0010:update_sit_entry+0x35d/0x3e0 Call Trace: f2fs_allocate_data_block+0x16c/0x5a0 do_write_page+0x57/0x100 f2fs_do_write_node_page+0x33/0xa0 __write_node_page+0x270/0x4e0 f2fs_sync_node_pages+0x5df/0x670 f2fs_write_checkpoint+0x364/0x13a0 f2fs_sync_fs+0xa3/0x130 f2fs_do_sync_file+0x1a6/0x810 do_fsync+0x33/0x60 __x64_sys_fsync+0xb/0x10 do_syscall_64+0x43/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The testcase fails because that, in fuzzed image, current segment was allocated with LFS type, its .next_blkoff should point to an unused block address, but actually, its bitmap shows it's not. So during allocation, f2fs crash when setting bitmap. Introducing sanity_check_curseg() to check such inconsistence of current in-used segment. 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 | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 291f7106537c7..0a6be0212e390 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -4242,6 +4242,41 @@ static int build_dirty_segmap(struct f2fs_sb_info *sbi) return init_victim_secmap(sbi); } +static int sanity_check_curseg(struct f2fs_sb_info *sbi) +{ + int i; + + /* + * In LFS/SSR curseg, .next_blkoff should point to an unused blkaddr; + * In LFS curseg, all blkaddr after .next_blkoff should be unused. + */ + for (i = 0; i < NO_CHECK_TYPE; i++) { + struct curseg_info *curseg = CURSEG_I(sbi, i); + struct seg_entry *se = get_seg_entry(sbi, curseg->segno); + unsigned int blkofs = curseg->next_blkoff; + + if (f2fs_test_bit(blkofs, se->cur_valid_map)) + goto out; + + if (curseg->alloc_type == SSR) + continue; + + for (blkofs += 1; blkofs < sbi->blocks_per_seg; blkofs++) { + if (!f2fs_test_bit(blkofs, se->cur_valid_map)) + continue; +out: + f2fs_msg(sbi->sb, KERN_ERR, + "Current segment's next free block offset is " + "inconsistent with bitmap, logtype:%u, " + "segno:%u, type:%u, next_blkoff:%u, blkofs:%u", + i, curseg->segno, curseg->alloc_type, + curseg->next_blkoff, blkofs); + return -EINVAL; + } + } + return 0; +} + /* * Update min, max modified time for cost-benefit GC algorithm */ @@ -4337,6 +4372,10 @@ int f2fs_build_segment_manager(struct f2fs_sb_info *sbi) if (err) return err; + err = sanity_check_curseg(sbi); + if (err) + return err; + init_min_max_mtime(sbi); return 0; } -- 2.20.1
