From: Chao Yu yuchao0@huawei.com
[ Upstream commit 7b63f72f73af57bb040f03b9713ec9979d8911f4 ]
As Jungyeon reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=203229
- Overview When mounting the attached crafted image, following errors are reported. Additionally, it hangs on sync after trying to mount it.
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 mkdir test mount -t f2fs tmp.img test sync
- Kernel message kernel BUG at fs/f2fs/recovery.c:591! RIP: 0010:recover_data+0x12d8/0x1780 Call Trace: f2fs_recover_fsync_data+0x613/0x710 f2fs_fill_super+0x1043/0x1aa0 mount_bdev+0x16d/0x1a0 mount_fs+0x4a/0x170 vfs_kern_mount+0x5d/0x100 do_mount+0x200/0xcf0 ksys_mount+0x79/0xc0 __x64_sys_mount+0x1c/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9
With corrupted image wihch has out-of-range valid node/block count, during recovery, once we failed due to no free space, it will trigger kernel panic.
Adding sanity check on valid node/block count in f2fs_sanity_check_ckpt() to detect such condition, so that potential panic can be avoided.
Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/super.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 6851afc3bf805..3fc96cffe6ac5 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2344,7 +2344,8 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi) unsigned int log_blocks_per_seg; unsigned int segment_count_main; unsigned int cp_pack_start_sum, cp_payload; - block_t user_block_count; + block_t user_block_count, valid_user_blocks; + block_t avail_node_count, valid_node_count; int i, j;
total = le32_to_cpu(raw_super->segment_count); @@ -2379,6 +2380,24 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi) return 1; }
+ valid_user_blocks = le64_to_cpu(ckpt->valid_block_count); + if (valid_user_blocks > user_block_count) { + f2fs_msg(sbi->sb, KERN_ERR, + "Wrong valid_user_blocks: %u, user_block_count: %u", + valid_user_blocks, user_block_count); + return 1; + } + + valid_node_count = le32_to_cpu(ckpt->valid_node_count); + avail_node_count = sbi->total_node_count - sbi->nquota_files - + F2FS_RESERVED_NODE_NUM; + if (valid_node_count > avail_node_count) { + f2fs_msg(sbi->sb, KERN_ERR, + "Wrong valid_node_count: %u, avail_node_count: %u", + valid_node_count, avail_node_count); + return 1; + } + main_segs = le32_to_cpu(raw_super->segment_count_main); blocks_per_seg = sbi->blocks_per_seg;