diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2025-09-16 17:20:59 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2025-09-18 17:24:59 +0800 |
| commit | 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 (patch) | |
| tree | 83ba47edc03f003d2f13f2875df1de1259c09b77 | |
| parent | 9574b2330dbd2b5459b74d3b5e9619d39299fc6f (diff) | |
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
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>
| -rw-r--r-- | crypto/af_alg.c | 7 | ||||
| -rw-r--r-- | include/crypto/if_alg.h | 10 |
2 files changed, 13 insertions, 4 deletions
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 407f2c238f2c..ca6fdcc6c54a 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -970,6 +970,12 @@ 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; @@ -1105,6 +1111,7 @@ 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; diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index f7b3b93f3a49..0c70f3a55575 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -135,6 +135,7 @@ struct af_alg_async_req { * SG? * @enc: Cryptographic operation to be performed when * recvmsg is invoked. + * @write: True if we are in the middle of a write. * @init: True if metadata has been sent. * @len: Length of memory allocated for this data structure. * @inflight: Non-zero when AIO requests are in flight. @@ -151,10 +152,11 @@ struct af_alg_ctx { size_t used; atomic_t rcvused; - bool more; - bool merge; - bool enc; - bool init; + u32 more:1, + merge:1, + enc:1, + write:1, + init:1; unsigned int len; |