diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2025-09-22 14:44:49 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-25 10:58:55 +0200 |
| commit | 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 (patch) | |
| tree | e16fa286c007505ef0e5693bd19997002f9e4501 /crypto | |
| parent | 2b8bbc64b5c228cebd52bd03470d70ba781d1915 (diff) | |
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
[ Upstream commit 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 ]
Issuing two writes to the same af_alg socket is bogus as the
data will be interleaved in an unpredictable fashion. Furthermore,
concurrent writes may create inconsistencies in the internal
socket state.
Disallow this by adding a new ctx->write field that indiciates
exclusive ownership for writing.
Fixes: 8ff590903d5 ("crypto: algif_skcipher - User-space interface for skcipher operations")
Reported-by: Muhammad Alifa Ramdhan <ramdhan@starlabs.sg>
Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/af_alg.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 1e03bb481ce0..3e333be303fe 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -859,6 +859,12 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, } lock_sock(sk); + if (ctx->write) { + release_sock(sk); + return -EBUSY; + } + ctx->write = true; + if (ctx->init && !ctx->more) { if (ctx->used) { err = -EINVAL; @@ -974,6 +980,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, unlock: af_alg_data_wakeup(sk); + ctx->write = false; release_sock(sk); return copied ?: err; |