From c954e7cc4ba79a7fedef7dd66c8993381172d78e Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Sun, 1 Nov 2020 20:53:31 +0800 Subject: [PATCH] fsck.f2fs: do xnid sanity check only during fsck As Eric reported: Commit 7a22451bc2b4 ("fsck.f2fs: fix to check validation of i_xattr_nid") This commit caused a regression where 'dump.f2fs -i ' now segfaults if the inode has any extended attributes. It's because read_all_xattrs() now calls fsck_sanity_check_nid(), which eventually dereferences f2fs_fsck::main_area_bitmap, which is NULL. I'm not sure what was intended here. Here's the output from gdb: Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7f750fa in f2fs_test_bit (nr=1024, p=0x0) at libf2fs.c:304 304 return (mask & *addr) != 0; (gdb) bt ntype=TYPE_XATTR, ni=0x7fffffffdd20) at fsck.c:449 ntype=TYPE_XATTR, ni=0x7fffffffdd20) at fsck.c:495 fsck_sanity_check_nid() should only called from fsck.f2fs context, rather than dump.f2fs, otherwise it may cause dereferencing structure fields of fsck incorrectly. Signed-off-by: Chao Yu --- fsck/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fsck/xattr.c b/fsck/xattr.c index e9dcb52..f0c5343 100644 --- a/fsck/xattr.c +++ b/fsck/xattr.c @@ -24,7 +24,7 @@ void *read_all_xattrs(struct f2fs_sb_info *sbi, struct f2fs_node *inode) u64 inline_size = inline_xattr_size(&inode->i); nid_t xnid = le32_to_cpu(inode->i.i_xattr_nid); - if (xnid) { + if (c.func == FSCK && xnid) { struct f2fs_node *node_blk = NULL; struct node_info ni; int ret;