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authorHarshit Mogalapalli <[email protected]>2022-04-13 04:42:51 -0700
committerSteve French <[email protected]>2022-04-13 12:00:49 -0500
commit64c4a37ac04eeb43c42d272f6e6c8c12bfcf4304 (patch)
treeee678309f2a4a7c47664fc0a436d5d6968046c65
parent1ddff774164f1bcd0fcf988f7a5bb24270fbdf2c (diff)
cifs: potential buffer overflow in handling symlinks
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 <[email protected]> Reviewed-by: Ronnie Sahlberg <[email protected]> Signed-off-by: Steve French <[email protected]>
-rw-r--r--fs/cifs/link.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 852e54ee82c2..bbdf3281559c 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -85,6 +85,9 @@ parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
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);