From 1c3e295f67d0ab05a8ecd071b4607711d94faa9f Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 15 Apr 2019 15:30:50 +0800 Subject: [PATCH] f2fs: fix to do sanity check on valid node/block count 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 Signed-off-by: Jaegeuk Kim --- 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 dd5658b1750f..6d9ee5e9c515 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2596,7 +2596,8 @@ 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); @@ -2631,6 +2632,24 @@ 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; -- 2.11.0