NFS: Fix leak of ctx->nfs_server.hostname
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Message ID 20200225160522.225406-1-smayhew@redhat.com
State New
Headers show
Series
  • NFS: Fix leak of ctx->nfs_server.hostname
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Commit Message

Scott Mayhew Feb. 25, 2020, 4:05 p.m. UTC
If userspace passes an nfs_mount_data struct in the data argument of
mount(2), then nfs23_parse_monolithic() or nfs4_parse_monolithic()
will allocate memory for ctx->nfs_server.hostname.  This needs to be
freed in nfs_parse_source(), which also allocates memory for
ctx->nfs_server.hostname, otherwise a leak will occur.

Reported-by: syzbot+193c375dcddb4f345091@syzkaller.appspotmail.com
Fixes: f2aedb713c28 ("NFS: Add fs_context support.")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 fs/nfs/fs_context.c | 2 ++
 1 file changed, 2 insertions(+)

Patch
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diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index b616263b0eb6..e113fcb4bb4c 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -832,6 +832,8 @@  static int nfs_parse_source(struct fs_context *fc,
 	if (len > maxnamlen)
 		goto out_hostname;
 
+	kfree(ctx->nfs_server.hostname);
+
 	/* N.B. caller will free nfs_server.hostname in all cases */
 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
 	if (!ctx->nfs_server.hostname)