diff options
| author | Len Baker <len.baker@gmx.com> | 2021-08-17 12:27:09 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 11:41:21 +0200 |
| commit | 0955df2d9bf4857e3e2287e3028903e6cec06c30 (patch) | |
| tree | cf1e52eccb68aa93cc407167e8898255c736d94a | |
| parent | 4179f4376ecb2b89d4fa31e7d1e6f2721b618f0d (diff) | |
CIFS: Fix a potencially linear read overflow
[ Upstream commit f980d055a0f858d73d9467bb0b570721bbfcdfb8 ]
strlcpy() reads the entire source buffer first. This read may exceed the
destination size limit. This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated.
Also, the strnlen() call does not avoid the read overflow in the strlcpy
function when a not NUL-terminated string is passed.
So, replace this block by a call to kstrndup() that avoids this type of
overflow and does the same.
Fixes: 066ce6899484d ("cifs: rename cifs_strlcpy_to_host and make it use new functions")
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/cifs/cifs_unicode.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c index 942874257a09..e5e780145728 100644 --- a/fs/cifs/cifs_unicode.c +++ b/fs/cifs/cifs_unicode.c @@ -367,14 +367,9 @@ cifs_strndup_from_utf16(const char *src, const int maxlen, if (!dst) return NULL; cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage, - NO_MAP_UNI_RSVD); + NO_MAP_UNI_RSVD); } else { - len = strnlen(src, maxlen); - len++; - dst = kmalloc(len, GFP_KERNEL); - if (!dst) - return NULL; - strlcpy(dst, src, len); + dst = kstrndup(src, maxlen, GFP_KERNEL); } return dst; |