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| author | Fedor Pchelkin <pchelkin@ispras.ru> | 2023-12-06 23:09:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-08 11:25:04 +0100 |
| commit | 21d33e353fb1edd109c68ded5308222ab69bce2c (patch) | |
| tree | fa16388e47c5126769bcc9ceb703b322926144e9 | |
| parent | 3abc53a64e0ab44041e8d2ba852806dfa0c8c421 (diff) | |
| download | linux-stable-21d33e353fb1edd109c68ded5308222ab69bce2c.tar.gz linux-stable-21d33e353fb1edd109c68ded5308222ab69bce2c.tar.bz2 linux-stable-21d33e353fb1edd109c68ded5308222ab69bce2c.zip | |
net: 9p: avoid freeing uninit memory in p9pdu_vreadf
commit ff49bf1867578f23a5ffdd38f927f6e1e16796c4 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/9p/protocol.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/net/9p/protocol.c b/net/9p/protocol.c index 1885403c9a3e..31e37af6109c 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -243,6 +243,8 @@ 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) { @@ -251,6 +253,8 @@ p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt, GFP_NOFS); if (!*wnames) errcode = -ENOMEM; + else + (*wnames)[0] = NULL; } if (!errcode) { @@ -262,8 +266,10 @@ 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; + } } } @@ -271,11 +277,14 @@ 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; |