From: Chao Yu <yuchao0@xxxxxxxxxx> [ Upstream commit 6a257471fa42c8c9c04a875cd3a2a22db148e0f0 ] As syzbot reported: kernel BUG at fs/f2fs/segment.h:657! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 16220 Comm: syz-executor.0 Not tainted 5.9.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:f2fs_ra_meta_pages+0xa51/0xdc0 fs/f2fs/segment.h:657 Call Trace: build_sit_entries fs/f2fs/segment.c:4195 [inline] f2fs_build_segment_manager+0x4b8a/0xa3c0 fs/f2fs/segment.c:4779 f2fs_fill_super+0x377d/0x6b80 fs/f2fs/super.c:3633 mount_bdev+0x32e/0x3f0 fs/super.c:1417 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] path_mount+0x1387/0x2070 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount fs/namespace.c:3390 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 @blkno in f2fs_ra_meta_pages could exceed max segment count, causing panic in following sanity check in current_sit_addr(), add check condition to avoid this issue. Reported-by: syzbot+3698081bcf0bb2d12174@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/checkpoint.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index eab37a7dca5f5..0f2286e57907c 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -202,6 +202,8 @@ int ra_meta_pages(struct f2fs_sb_info *sbi, block_t start, int nrpages, blkno * NAT_ENTRY_PER_BLOCK); break; case META_SIT: + if (unlikely(blkno >= TOTAL_SEGS(sbi))) + goto out; /* get sit block addr */ fio.new_blkaddr = current_sit_addr(sbi, blkno * SIT_ENTRY_PER_BLOCK); -- 2.27.0
