From baac16c4dbe45a4b8974bd24da789b0310a1dae7 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 24 Nov 2025 16:37:02 +0800 Subject: [PATCH 1/2] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg stable inclusion from stable-v6.6.108 commit 7c4491b5644e3a3708f3dbd7591be0a570135b84 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID1OXK CVE: CVE-2025-39964 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7c4491b5644e3a3708f3dbd7591be0a570135b84 -------------------------------- 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 Reported-by: Bing-Jhong Billy Jheng Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman Signed-off-by: Gu Bowen --- crypto/af_alg.c | 7 +++++++ 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 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; diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index bb5f20644786..384684b36aaa 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -140,6 +140,7 @@ 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. @@ -155,10 +156,11 @@ 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; -- Gitee From 2e136a40c962b2ef628c61a9c105153839006bed Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 24 Nov 2025 16:37:03 +0800 Subject: [PATCH 2/2] crypto: af_alg - Fix incorrect boolean values in af_alg_ctx stable inclusion from stable-v6.6.108 commit 8703940bd30b5ad94408d28d7192db2491cd3592 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID1OXK CVE: CVE-2025-39964 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8703940bd30b5ad94408d28d7192db2491cd3592 -------------------------------- commit d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb upstream. Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C's implicit conversion to bool, such that zero becomes false and nonzero becomes true. With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken instead, resulting in 0 being assigned in some cases when 1 was intended. Fix this by restoring the bool type. Fixes: 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Gu Bowen --- include/crypto/if_alg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index 384684b36aaa..2e43d7704d1d 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -156,7 +156,7 @@ struct af_alg_ctx { size_t used; atomic_t rcvused; - u32 more:1, + bool more:1, merge:1, enc:1, write:1, -- Gitee