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author | Eugene Korenevsky <ekorenevsky@astralinux.ru> | 2021-04-16 09:35:30 +0200 |
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committer | Steve French <stfrench@microsoft.com> | 2021-04-25 23:28:24 +0200 |
commit | a637f4ae037e1e0604ac008564934d63261a8fd1 (patch) | |
tree | 6a493b841d7fc45d87431b30a7dd3e21ccac6c44 /fs/cifs | |
parent | smb2: fix use-after-free in smb2_ioctl_query_info() (diff) | |
download | linux-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.c | 2 |
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; |