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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2025-09-16 17:20:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-09-25 11:00:07 +0200 |
| commit | 7c4491b5644e3a3708f3dbd7591be0a570135b84 (patch) | |
| tree | 82f94aa9287956436b54b2caa1279449ace261b9 /crypto | |
| parent | ee74d69af1707030cc409f1a07b79fd1d3aa24b4 (diff) | |
| download | linux-7c4491b5644e3a3708f3dbd7591be0a570135b84.tar.gz linux-7c4491b5644e3a3708f3dbd7591be0a570135b84.tar.bz2 linux-7c4491b5644e3a3708f3dbd7591be0a570135b84.zip | |
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
commit 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 upstream.
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: 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 68cc9290cabe..dbddcf52b992 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -969,6 +969,12 @@ 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; @@ -1103,6 +1109,7 @@ 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; |