[PATCH 5.4 380/389] f2fs: fix to avoid use f2fs_bug_on() in f2fs_new_node_page()

Greg Kroah-Hartman
2022-08-23T12:06:49Z

From: Chao Yu <chao.yu@oppo.com>

[ Upstream commit 141170b759e03958f296033bb7001be62d1d363b ]

As Dipanjan Das <mail.dipanjan.das@gmail.com> reported, syzkaller
found a f2fs bug as below:

RIP: 0010:f2fs_new_node_page+0x19ac/0x1fc0 fs/f2fs/node.c:1295
Call Trace:
write_all_xattrs fs/f2fs/xattr.c:487 [inline]
__f2fs_setxattr+0xe76/0x2e10 fs/f2fs/xattr.c:743
f2fs_setxattr+0x233/0xab0 fs/f2fs/xattr.c:790
f2fs_xattr_generic_set+0x133/0x170 fs/f2fs/xattr.c:86
__vfs_setxattr+0x115/0x180 fs/xattr.c:182
__vfs_setxattr_noperm+0x125/0x5f0 fs/xattr.c:216
__vfs_setxattr_locked+0x1cf/0x260 fs/xattr.c:277
vfs_setxattr+0x13f/0x330 fs/xattr.c:303
setxattr+0x146/0x160 fs/xattr.c:611
path_setxattr+0x1a7/0x1d0 fs/xattr.c:630
__do_sys_lsetxattr fs/xattr.c:653 [inline]
__se_sys_lsetxattr fs/xattr.c:649 [inline]
__x64_sys_lsetxattr+0xbd/0x150 fs/xattr.c:649
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

NAT entry and nat bitmap can be inconsistent, e.g. one nid is free
in nat bitmap, and blkaddr in its NAT entry is not NULL_ADDR, it
may trigger BUG_ON() in f2fs_new_node_page(), fix it.

Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/node.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 3dc7cc3d6ac6..b080d5c58f6c 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1240,7 +1240,11 @@ struct page *f2fs_new_node_page(struct dnode_of_data *dn, unsigned int ofs)
dec_valid_node_count(sbi, dn->inode, !ofs);
goto fail;
}
- f2fs_bug_on(sbi, new_ni.blk_addr != NULL_ADDR);
+ if (unlikely(new_ni.blk_addr != NULL_ADDR)) {
+ err = -EFSCORRUPTED;
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ goto fail;
+ }
#endif
new_ni.nid = dn->nid;
new_ni.ino = dn->inode->i_ino;
--
2.35.1