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authorEugene Korenevsky <ekorenevsky@astralinux.ru>2021-04-16 09:35:30 +0200
committerSteve French <stfrench@microsoft.com>2021-04-25 23:28:24 +0200
commita637f4ae037e1e0604ac008564934d63261a8fd1 (patch)
tree6a493b841d7fc45d87431b30a7dd3e21ccac6c44 /fs/cifs
parentsmb2: fix use-after-free in smb2_ioctl_query_info() (diff)
downloadlinux-a637f4ae037e1e0604ac008564934d63261a8fd1.tar.xz
linux-a637f4ae037e1e0604ac008564934d63261a8fd1.zip
cifs: fix out-of-bound memory access when calling smb3_notify() at mount point
If smb3_notify() is called at mount point of CIFS, build_path_from_dentry() returns the pointer to kmalloc-ed memory with terminating zero (this is empty FileName to be passed to SMB2 CREATE request). This pointer is assigned to the `path` variable. Then `path + 1` (to skip first backslash symbol) is passed to cifs_convert_path_to_utf16(). This is incorrect for empty path and causes out-of-bound memory access. Get rid of this "increase by one". cifs_convert_path_to_utf16() already contains the check for leading backslash in the path. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212693 CC: <stable@vger.kernel.org> # v5.6+ Signed-off-by: Eugene Korenevsky <ekorenevsky@astralinux.ru> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/smb2ops.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 20f1fb66fc9e..60a474990924 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2264,7 +2264,7 @@ smb3_notify(const unsigned int xid, struct file *pfile,
goto notify_exit;
}
- utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
+ utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
if (utf16_path == NULL) {
rc = -ENOMEM;
goto notify_exit;