From e78232b3141ade2b69370ac215791b044a3d757e Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 14 Nov 2025 10:59:10 +0800 Subject: [PATCH 1/2] crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg mainline inclusion from mainline-v6.17-rc7 commit 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 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/torvalds/linux.git/commit/?id=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 Reported-by: Bing-Jhong Billy Jheng Signed-off-by: Herbert Xu 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 fdccf8c9c4ff..69c21b047566 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -865,6 +865,12 @@ 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; @@ -972,6 +978,7 @@ 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 9ff2826cdd48..db6480e95948 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 d8124bd2f365d606f65b69047fdf791bf5aec8f2 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 14 Nov 2025 10:59:11 +0800 Subject: [PATCH 2/2] crypto: af_alg - Fix incorrect boolean values in af_alg_ctx mainline inclusion from mainline-v6.17 commit d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb 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/torvalds/linux.git/commit/?id=d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb ------------------------------- 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: 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 db6480e95948..ca3cd8118639 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