[PATCH] fs: hfsplus: fix uninit-value bug in hfsplus_listxattr

From: houweitao
Date: Tue May 09 2023 - 22:27:29 EST


BUG: KMSAN: uninit-value in strncmp+0x11e/0x180 lib/string.c:307
strncmp+0x11e/0x180 lib/string.c:307
is_known_namespace fs/hfsplus/xattr.c:45 [inline]
name_len fs/hfsplus/xattr.c:397 [inline]
hfsplus_listxattr+0xe61/0x1aa0 fs/hfsplus/xattr.c:746
vfs_listxattr fs/xattr.c:473 [inline]
listxattr+0x700/0x780 fs/xattr.c:820
path_listxattr fs/xattr.c:844 [inline]
__do_sys_llistxattr fs/xattr.c:862 [inline]
__se_sys_llistxattr fs/xattr.c:859 [inline]
__ia32_sys_llistxattr+0x171/0x300 fs/xattr.c:859
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
entry_SYSENTER_compat_after_hwframe+0x70/0x82

Reported-by: syzbot <syzbot+92ef9ee419803871020e@xxxxxxxxxxxxxxxxxxxxxxxxx>
Link: https://syzkaller.appspot.com/bug?extid=92ef9ee419803871020e
Signed-off-by: houweitao <houweitao@xxxxxxxxxxxxxx>
---
fs/hfsplus/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index 58021e73c00b..f7f9d0889df3 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -698,7 +698,7 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
return err;
}

- strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
+ strbuf = kzalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
if (!strbuf) {
res = -ENOMEM;
--
2.17.1