[PATCH] reiserfs: fix null ptr deref in reiserfs_xattr_set

From: Edward Adam Davis
Date: Wed Jan 03 2024 - 07:40:37 EST


Before performing any xattr settings, it is necessary to first confirm that both
xattr_root and priv_root are valid.

Reported-and-tested-by: syzbot+74dce9511a59ad67a492@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx
---
fs/reiserfs/xattr.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 998035a6388e..00fd8f747394 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -618,6 +618,9 @@ int reiserfs_xattr_set(struct inode *inode, const char *name,
int error, error2;
size_t jbegin_count = reiserfs_xattr_nblocks(inode, buffer_size);

+ if (!reiserfs_xattrs_initialized(inode->i_sb))
+ return -EOPNOTSUPP;
+
/* Check before we start a transaction and then do nothing. */
if (!d_really_is_positive(REISERFS_SB(inode->i_sb)->priv_root))
return -EOPNOTSUPP;
--
2.43.0