| Message ID | 20220413114251.73083-1-harshit.m.mogalapalli@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] cifs: potential buffer overflow in handling symlinks | expand |
diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 852e54e..bbdf328 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -85,6 +85,9 @@ if (rc != 1) return -EINVAL; + if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN) + return -EINVAL; + rc = symlink_hash(link_len, link_str, md5_hash); if (rc) { cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
Smatch printed a warning: arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error: __memcpy() 'dctx->buf' too small (16 vs u32max) It's caused because Smatch marks 'link_len' as untrusted since it comes from sscanf(). Add a check to ensure that 'link_len' is not larger than the size of the 'link_str' buffer. Fixes: c69c1b6eaea1 ("cifs: implement CIFSParseMFSymlink()") Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> --- v2: make use of CIFS_MF_SYMLINK_LINK_MAXLEN (same but cleaner). fs/cifs/link.c | 3 +++ 1 file changed, 3 insertions(+)