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authorFedor Pchelkin <pchelkin@ispras.ru>2023-12-06 23:09:13 +0300
committerDominique Martinet <asmadeus@codewreck.org>2023-12-13 05:44:30 +0900
commitff49bf1867578f23a5ffdd38f927f6e1e16796c4 (patch)
tree29bb66d6e7e56da4a7ef5c9d8b7735dde42984e6
parenta931c6816078af3e306e0f444f492396ce40de31 (diff)
net: 9p: avoid freeing uninit memory in p9pdu_vreadf
If some of p9pdu_readf() calls inside case 'T' in p9pdu_vreadf() fails, the error path is not handled properly. *wnames or members of *wnames array may be left uninitialized and invalidly freed. Initialize *wnames to NULL in beginning of case 'T'. Initialize the first *wnames array element to NULL and nullify the failing *wnames element so that the error path freeing loop stops on the first NULL element and doesn't proceed further. Found by Linux Verification Center (linuxtesting.org). Fixes: ace51c4dd2f9 ("9p: add new protocol support code") Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Message-ID: <20231206200913.16135-1-pchelkin@ispras.ru> Cc: stable@vger.kernel.org Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
-rw-r--r--net/9p/protocol.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index 4e3a2a1ffcb3..0e6603b1ec90 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -394,6 +394,8 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
uint16_t *nwname = va_arg(ap, uint16_t *);
char ***wnames = va_arg(ap, char ***);
+ *wnames = NULL;
+
errcode = p9pdu_readf(pdu, proto_version,
"w", nwname);
if (!errcode) {
@@ -403,6 +405,8 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
GFP_NOFS);
if (!*wnames)
errcode = -ENOMEM;
+ else
+ (*wnames)[0] = NULL;
}
if (!errcode) {
@@ -414,8 +418,10 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
proto_version,
"s",
&(*wnames)[i]);
- if (errcode)
+ if (errcode) {
+ (*wnames)[i] = NULL;
break;
+ }
}
}
@@ -423,11 +429,14 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
if (*wnames) {
int i;
- for (i = 0; i < *nwname; i++)
+ for (i = 0; i < *nwname; i++) {
+ if (!(*wnames)[i])
+ break;
kfree((*wnames)[i]);
+ }
+ kfree(*wnames);
+ *wnames = NULL;
}
- kfree(*wnames);
- *wnames = NULL;
}
}
break;