This is a note to let you know that I've just added the patch titled
nfs: fix possible null-ptr-deref when parsing param
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfs-fix-possible-null-ptr-deref-when-parsing-param.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0602f9076aa604a9c10167c4dbdcb24f5f46fb07
Author: Hawkins Jiawei <yin31149@xxxxxxxxx>
Date: Mon Oct 24 00:39:45 2022 +0800
nfs: fix possible null-ptr-deref when parsing param
[ Upstream commit 5559405df652008e56eee88872126fe4c451da67 ]
According to commit "vfs: parse: deal with zero length string value",
kernel will set the param->string to null pointer in vfs_parse_fs_string()
if fs string has zero length.
Yet the problem is that, nfs_fs_context_parse_param() will dereferences the
param->string, without checking whether it is a null pointer, which may
trigger a null-ptr-deref bug.
This patch solves it by adding sanity check on param->string
in nfs_fs_context_parse_param().
Signed-off-by: Hawkins Jiawei <yin31149@xxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 09833ec102fc..9bcd53d5c7d4 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -684,6 +684,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
return ret;
break;
case Opt_vers:
+ if (!param->string)
+ goto out_invalid_value;
trace_nfs_mount_assign(param->key, param->string);
ret = nfs_parse_version_string(fc, param->string);
if (ret < 0)
@@ -696,6 +698,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
break;
case Opt_proto:
+ if (!param->string)
+ goto out_invalid_value;
trace_nfs_mount_assign(param->key, param->string);
protofamily = AF_INET;
switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
@@ -732,6 +736,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc,
break;
case Opt_mountproto:
+ if (!param->string)
+ goto out_invalid_value;
trace_nfs_mount_assign(param->key, param->string);
mountfamily = AF_INET;
switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
