From: Chao Yu yuchao0@huawei.com
[ Upstream commit b42b179bda9ff11075a6fc2bac4d9e400513679a ]
As Jungyeon reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=203221
- Overview When mounting the attached crafted image and running program, this error is reported.
The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on.
- Reproduces cc poc_07.c mkdir test mount -t f2fs tmp.img test cp a.out test cd test sudo ./a.out
- Messages kernel BUG at fs/f2fs/node.c:1279! RIP: 0010:read_node_page+0xcf/0xf0 Call Trace: __get_node_page+0x6b/0x2f0 f2fs_iget+0x8f/0xdf0 f2fs_lookup+0x136/0x320 __lookup_slow+0x92/0x140 lookup_slow+0x30/0x50 walk_component+0x1c1/0x350 path_lookupat+0x62/0x200 filename_lookup+0xb3/0x1a0 do_fchmodat+0x3e/0xa0 __x64_sys_chmod+0x12/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9
On below paths, we can have opportunity to readahead inode page - gc_node_segment -> f2fs_ra_node_page - gc_data_segment -> f2fs_ra_node_page - f2fs_fill_dentries -> f2fs_ra_node_page
Unlike synchronized read, on readahead path, we can set page uptodate before verifying page's checksum, then read_node_page() will trigger kernel panic once it encounters a uptodated page w/ incorrect checksum.
So considering readahead scenario, we have to do checksum each time when loading inode page even if it is uptodated.
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/inode.c | 4 ++-- fs/f2fs/node.c | 7 ++++--- 2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index fae9570e6860e..0f31df01e36c6 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -179,8 +179,8 @@ bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page)
if (provided != calculated) f2fs_msg(sbi->sb, KERN_WARNING, - "checksum invalid, ino = %x, %x vs. %x", - ino_of_node(page), provided, calculated); + "checksum invalid, nid = %lu, ino_of_node = %x, %x vs. %x", + page->index, ino_of_node(page), provided, calculated);
return provided == calculated; } diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 34c3f732601c3..e2d9edad758cd 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1282,9 +1282,10 @@ static int read_node_page(struct page *page, int op_flags) int err;
if (PageUptodate(page)) { -#ifdef CONFIG_F2FS_CHECK_FS - f2fs_bug_on(sbi, !f2fs_inode_chksum_verify(sbi, page)); -#endif + if (!f2fs_inode_chksum_verify(sbi, page)) { + ClearPageUptodate(page); + return -EBADMSG; + } return LOCKED_PAGE; }