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[PATCH OLK-5.10] nfsd: fix posix_acl leak on SETACL decode failure
by Lai Zewei 23 Jul '26

23 Jul '26

stable inclusion from stable-v5.10.260 commit b2eb1ffd511d1b3c3e21122f97cbbccea411e277 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16117 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling. ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure: svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */ The orphaned posix_acl is leaked for the lifetime of the server. Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures. Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") Cc: stable(a)vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Jeff Layton <jlayton(a)kernel.org> Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com> Conflicts: fs/nfsd/nfs2acl.c fs/nfsd/nfs3acl.c [ctx: conflicts] Signed-off-by: Lai Zewei <laizewei3(a)huawei.com> --- fs/nfsd/nfs2acl.c | 17 ++++++++++++----- fs/nfsd/nfs3acl.c | 17 ++++++++++++----- 2 files changed, 24 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c index 6a900f770dd2..b8bf3097dfe8 100644 --- a/fs/nfsd/nfs2acl.c +++ b/fs/nfsd/nfs2acl.c @@ -127,10 +127,7 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp) resp->status = fh_getattr(fh, &resp->stat); out: - /* argp->acl_{access,default} may have been allocated in - nfssvc_decode_setaclargs. */ - posix_acl_release(argp->acl_access); - posix_acl_release(argp->acl_default); + /* argp->acl_{access,default} are released in nfsaclsvc_release_setacl. */ return rpc_success; out_drop_lock: @@ -368,6 +365,16 @@ static void nfsaclsvc_release_access(struct svc_rqst *rqstp) fh_put(&resp->fh); } +static void nfsaclsvc_release_setacl(struct svc_rqst *rqstp) +{ + struct nfsd3_setaclargs *argp = rqstp->rq_argp; + struct nfsd_attrstat *resp = rqstp->rq_resp; + + fh_put(&resp->fh); + posix_acl_release(argp->acl_access); + posix_acl_release(argp->acl_default); +} + struct nfsd3_voidargs { int dummy; }; #define ST 1 /* status*/ @@ -399,7 +406,7 @@ static const struct svc_procedure nfsd_acl_procedures2[5] = { .pc_func = nfsacld_proc_setacl, .pc_decode = nfsaclsvc_decode_setaclargs, .pc_encode = nfsaclsvc_encode_attrstatres, - .pc_release = nfsaclsvc_release_attrstat, + .pc_release = nfsaclsvc_release_setacl, .pc_argsize = sizeof(struct nfsd3_setaclargs), .pc_ressize = sizeof(struct nfsd_attrstat), .pc_cachetype = RC_NOCACHE, diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c index 34a394e50e1d..80aa209fd046 100644 --- a/fs/nfsd/nfs3acl.c +++ b/fs/nfsd/nfs3acl.c @@ -114,10 +114,7 @@ static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp) out_errno: resp->status = nfserrno(error); out: - /* argp->acl_{access,default} may have been allocated in - nfs3svc_decode_setaclargs. */ - posix_acl_release(argp->acl_access); - posix_acl_release(argp->acl_default); + /* argp->acl_{access,default} are released in nfs3svc_release_setacl. */ return rpc_success; } @@ -235,6 +232,16 @@ static void nfs3svc_release_getacl(struct svc_rqst *rqstp) posix_acl_release(resp->acl_default); } +static void nfs3svc_release_setacl(struct svc_rqst *rqstp) +{ + struct nfsd3_setaclargs *argp = rqstp->rq_argp; + struct nfsd3_attrstat *resp = rqstp->rq_resp; + + fh_put(&resp->fh); + posix_acl_release(argp->acl_access); + posix_acl_release(argp->acl_default); +} + struct nfsd3_voidargs { int dummy; }; #define ST 1 /* status*/ @@ -266,7 +273,7 @@ static const struct svc_procedure nfsd_acl_procedures3[3] = { .pc_func = nfsd3_proc_setacl, .pc_decode = nfs3svc_decode_setaclargs, .pc_encode = nfs3svc_encode_setaclres, - .pc_release = nfs3svc_release_fhandle, + .pc_release = nfs3svc_release_setacl, .pc_argsize = sizeof(struct nfsd3_setaclargs), .pc_ressize = sizeof(struct nfsd3_attrstat), .pc_cachetype = RC_NOCACHE, -- 2.52.0

2 1

[PATCH OLK-6.6] NFSD: Fix SECINFO_NO_NAME decode error cleanup
by Lai Zewei 23 Jul '26

23 Jul '26

stable inclusion from stable-v6.6.144 commit 1e04be34cafae119e82bcaccd6d28a20f72a3647 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16118 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- nfsd4_decode_secinfo_no_name() currently initializes sin_exp after decoding sin_style. If the XDR stream is truncated, the decoder returns nfserr_bad_xdr before sin_exp is initialized. Since commit 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing"), the inline iops array is not cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore leave sin_exp holding stale union contents from a previous operation. The error response path still invokes nfsd4_secinfo_no_name_release(), which calls exp_put() on a non-NULL sin_exp. Initialize sin_exp before the first failable decode step, matching nfsd4_decode_secinfo(). Fixes: 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing") Cc: stable(a)vger.kernel.org Signed-off-by: Guannan Wang <wgnbuaa(a)gmail.com> Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com> Signed-off-by: Lai Zewei <laizewei3(a)huawei.com> --- fs/nfsd/nfs4xdr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 03a4a8de1114..e3b128cc2413 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1821,10 +1821,11 @@ static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u) { struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name; + + sin->sin_exp = NULL; if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0) return nfserr_bad_xdr; - sin->sin_exp = NULL; return nfs_ok; } -- 2.52.0

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[PATCH OLK-6.6] nfsd: fix posix_acl leak on SETACL decode failure
by Lai Zewei 23 Jul '26

23 Jul '26

stable inclusion from stable-v5.10.260 commit b2eb1ffd511d1b3c3e21122f97cbbccea411e277 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16117 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling. ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure: svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */ The orphaned posix_acl is leaked for the lifetime of the server. Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures. Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") Cc: stable(a)vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Jeff Layton <jlayton(a)kernel.org> Signed-off-by: Chuck Lever <chuck.lever(a)oracle.com> Conflicts: fs/nfsd/nfs2acl.c fs/nfsd/nfs3acl.c [ctx conflicts] Signed-off-by: Lai Zewei <laizewei3(a)huawei.com> --- fs/nfsd/nfs2acl.c | 17 ++++++++++++----- fs/nfsd/nfs3acl.c | 17 ++++++++++++----- 2 files changed, 24 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c index f1f32ad4f42c..b21e89c0df33 100644 --- a/fs/nfsd/nfs2acl.c +++ b/fs/nfsd/nfs2acl.c @@ -131,10 +131,7 @@ static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp) resp->status = fh_getattr(fh, &resp->stat); out: - /* argp->acl_{access,default} may have been allocated in - nfssvc_decode_setaclargs. */ - posix_acl_release(argp->acl_access); - posix_acl_release(argp->acl_default); + /* argp->acl_{access,default} are released in nfsaclsvc_release_setacl. */ return rpc_success; out_drop_lock: @@ -310,6 +307,16 @@ static void nfsaclsvc_release_access(struct svc_rqst *rqstp) fh_put(&resp->fh); } +static void nfsaclsvc_release_setacl(struct svc_rqst *rqstp) +{ + struct nfsd3_setaclargs *argp = rqstp->rq_argp; + struct nfsd_attrstat *resp = rqstp->rq_resp; + + fh_put(&resp->fh); + posix_acl_release(argp->acl_access); + posix_acl_release(argp->acl_default); +} + struct nfsd3_voidargs { int dummy; }; #define ST 1 /* status*/ @@ -345,7 +352,7 @@ static const struct svc_procedure nfsd_acl_procedures2[5] = { .pc_func = nfsacld_proc_setacl, .pc_decode = nfsaclsvc_decode_setaclargs, .pc_encode = nfssvc_encode_attrstatres, - .pc_release = nfssvc_release_attrstat, + .pc_release = nfsaclsvc_release_setacl, .pc_argsize = sizeof(struct nfsd3_setaclargs), .pc_argzero = sizeof(struct nfsd3_setaclargs), .pc_ressize = sizeof(struct nfsd_attrstat), diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c index d7af28f44504..e7ee0b409313 100644 --- a/fs/nfsd/nfs3acl.c +++ b/fs/nfsd/nfs3acl.c @@ -118,10 +118,7 @@ static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp) out_errno: resp->status = nfserrno(error); out: - /* argp->acl_{access,default} may have been allocated in - nfs3svc_decode_setaclargs. */ - posix_acl_release(argp->acl_access); - posix_acl_release(argp->acl_default); + /* argp->acl_{access,default} are released in nfs3svc_release_setacl. */ return rpc_success; } @@ -223,6 +220,16 @@ static void nfs3svc_release_getacl(struct svc_rqst *rqstp) posix_acl_release(resp->acl_default); } +static void nfs3svc_release_setacl(struct svc_rqst *rqstp) +{ + struct nfsd3_setaclargs *argp = rqstp->rq_argp; + struct nfsd3_attrstat *resp = rqstp->rq_resp; + + fh_put(&resp->fh); + posix_acl_release(argp->acl_access); + posix_acl_release(argp->acl_default); +} + struct nfsd3_voidargs { int dummy; }; #define ST 1 /* status*/ @@ -258,7 +265,7 @@ static const struct svc_procedure nfsd_acl_procedures3[3] = { .pc_func = nfsd3_proc_setacl, .pc_decode = nfs3svc_decode_setaclargs, .pc_encode = nfs3svc_encode_setaclres, - .pc_release = nfs3svc_release_fhandle, + .pc_release = nfs3svc_release_setacl, .pc_argsize = sizeof(struct nfsd3_setaclargs), .pc_argzero = sizeof(struct nfsd3_setaclargs), .pc_ressize = sizeof(struct nfsd3_attrstat), -- 2.52.0

2 1

[PATCH OLK-6.6] virtiofs: fix UAF on submount umount
by Lai Zewei 23 Jul '26

23 Jul '26

stable inclusion from stable-v6.6.144 commit 2181a09ba980f142650fb053666350ead4471cfe category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16101 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- iput() called from fuse_release_end() can Oops if the super block has already been destroyed. Normally this is prevented by waiting for num_waiting to go down to zero before commencing with super block shutdown. This only works, however, for the last submount instance, as the wait counter is per connection, not per superblock. Revert to using synchronous release requests for the auto_submounts case, which is virtiofs only at this time. Reported-by: Aurélien Bombo <abombo(a)microsoft.com> Reported-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Cc: Greg Kurz <gkurz(a)redhat.com> Closes: https://github.com/kata-containers/kata-containers/issues/12589 Fixes: 26e5c67deb2e ("fuse: fix livelock in synchronous file put from fuseblk workers") Cc: stable(a)vger.kernel.org Reviewed-by: Greg Kurz <gkurz(a)redhat.com> Signed-off-by: Miklos Szeredi <mszeredi(a)redhat.com> Signed-off-by: Lai Zewei <laizewei3(a)huawei.com> --- fs/fuse/file.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index cd0a24f029a4..1d6bfdf22d19 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -373,8 +373,14 @@ void fuse_file_release(struct inode *inode, struct fuse_file *ff, * aio and closes the fd before the aio completes. Since aio takes its * own ref to the file, the IO completion has to drop the ref, which is * how the fuse server can end up closing its clients' files. + * + * Exception is virtio-fs, which is not affected by the above (server is + * on host, cannot close open files in guest). Virtio-fs needs sync + * release, because the num_waiting mechanism to wait for all requests + * before commencing with fs shutdown doesn't work if submounts are + * used. */ - fuse_file_put(ff, false); + fuse_file_put(ff, ff->fm->fc->auto_submounts); } void fuse_release_common(struct file *file, bool isdir) -- 2.52.0

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[PATCH OLK-5.10] l2tp: pppol2tp: hold reference to session in pppol2tp_ioctl()
by Gu Bowen 23 Jul '26

23 Jul '26

From: Lee Jones <lee(a)kernel.org> mainline inclusion from mainline-v7.1-rc7 commit a213a8950414c684999dcf03edeea6c46ede172e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15948 CVE: CVE-2026-53262 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- pppol2tp_ioctl() read sock->sk->sk_user_data directly without any locks or reference counting. If a controllable sleep was induced during copy_from_user() (e.g. via a userfaultfd page fault sleep), a concurrent socket close could trigger pppol2tp_session_close() asynchronously. This frees the l2tp_session structure via the l2tp_session_del_work workqueue. Upon resuming, the ioctl thread dereferences the stale session pointer, resulting in a Use-After-Free (UAF). Fix this by securely fetching the session reference using the RCU-safe, refcounted helper pppol2tp_sock_to_session(sk) on entry. This locks the session's refcount across the sleep. We structured the function to exit via standard err breaks, guaranteeing that l2tp_session_put() is cleanly called on all return paths to drop the reference. To preserve existing behavior we validate the session and its magic signature only for the specific L2TP commands that require it. This ensures that generic/unknown ioctls called on an unconnected socket still return -ENOIOCTLCMD and correctly fall back to generic handlers (e.g. in sock_do_ioctl()). Signed-off-by: Lee Jones <lee(a)kernel.org> Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Link: https://patch.msgid.link/20260527133630.2120612-1-lee@kernel.org Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Conflicts: net/l2tp/l2tp_ppp.c [Function l2tp_session_put() conflicts due to mainline commit abe7a1a7d0b6 ("l2tp: improve tunnel/session refcount helpers") and commit c5cbaef992d64 ("l2tp: refactor ppp socket/session relationship") not merge.] Signed-off-by: Gu Bowen <gubowen5(a)huawei.com> --- net/l2tp/l2tp_ppp.c | 82 +++++++++++++++++++++++++++------------------ 1 file changed, 50 insertions(+), 32 deletions(-) diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index c53717192039..4e51e47bb4d3 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1066,64 +1066,76 @@ static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, { struct pppol2tp_ioc_stats stats; struct l2tp_session *session; + int err = 0; + + session = pppol2tp_sock_to_session(sock->sk); + /* Validate session presence and magic integrity ONLY for commands + * that belong to L2TP and require a valid session. + */ switch (cmd) { case PPPIOCGMRU: case PPPIOCGFLAGS: - session = sock->sk->sk_user_data; + case PPPIOCSMRU: + case PPPIOCSFLAGS: + case PPPIOCGL2TPSTATS: if (!session) return -ENOTCONN; - if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) + if (session->magic != L2TP_SESSION_MAGIC) { + sock_put(sock->sk); return -EBADF; + } + break; + default: + break; + } + switch (cmd) { + case PPPIOCGMRU: + case PPPIOCGFLAGS: /* Not defined for tunnels */ - if (!session->session_id && !session->peer_session_id) - return -ENOSYS; + if (!session->session_id && !session->peer_session_id) { + err = -ENOSYS; + break; + } - if (put_user(0, (int __user *)arg)) - return -EFAULT; + if (put_user(0, (int __user *)arg)) { + err = -EFAULT; + break; + } break; case PPPIOCSMRU: case PPPIOCSFLAGS: - session = sock->sk->sk_user_data; - if (!session) - return -ENOTCONN; - - if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) - return -EBADF; - /* Not defined for tunnels */ - if (!session->session_id && !session->peer_session_id) - return -ENOSYS; + if (!session->session_id && !session->peer_session_id) { + err = -ENOSYS; + break; + } - if (!access_ok((int __user *)arg, sizeof(int))) - return -EFAULT; + if (!access_ok((int __user *)arg, sizeof(int))) { + err = -EFAULT; + break; + } break; case PPPIOCGL2TPSTATS: - session = sock->sk->sk_user_data; - if (!session) - return -ENOTCONN; - - if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) - return -EBADF; - /* Session 0 represents the parent tunnel */ if (!session->session_id && !session->peer_session_id) { u32 session_id; - int err; if (copy_from_user(&stats, (void __user *)arg, - sizeof(stats))) - return -EFAULT; + sizeof(stats))) { + err = -EFAULT; + break; + } session_id = stats.session_id; err = pppol2tp_tunnel_copy_stats(&stats, session->tunnel); if (err < 0) - return err; + break; stats.session_id = session_id; } else { @@ -1133,15 +1145,21 @@ static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, stats.tunnel_id = session->tunnel->tunnel_id; stats.using_ipsec = l2tp_tunnel_uses_xfrm(session->tunnel); - if (copy_to_user((void __user *)arg, &stats, sizeof(stats))) - return -EFAULT; + if (copy_to_user((void __user *)arg, &stats, sizeof(stats))) { + err = -EFAULT; + break; + } break; default: - return -ENOIOCTLCMD; + err = -ENOIOCTLCMD; + break; } - return 0; + if (session) + sock_put(sock->sk); + + return err; } /***************************************************************************** -- 2.43.0

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openEuler Kernel SIG双周例会
by openEuler conference 23 Jul '26

23 Jul '26

您好！ Kernel 邀请您参加 2026-07-24 14:00 召开的WeLink会议(自动录制) 会议主题：openEuler Kernel SIG双周例会会议发起人： LiaoTao_Wave 会议内容： 1. 进展update 2. 议题征集中（新增议题可直接申报至会议纪要看板）会议链接：https://meeting.huaweicloud.com:36443/#/j/981821462 会议纪要&签到链接：https://etherpad.openeuler.org/p/Kernel-meetings 更多资讯尽在：https://www.openeuler.org/zh/ Hello! Kernel invites you to attend the WeLink conference(auto recording) will be held at 2026-07-24 14:00 The subject of the conference is openEuler Kernel SIG双周例会 The sponsor of the conference is LiaoTao_Wave Summary: 1. 进展update 2. 议题征集中（新增议题可直接申报至会议纪要看板） You can join the meeting at https://meeting.huaweicloud.com:36443/#/j/981821462 Add topics at https://etherpad.openeuler.org/p/Kernel-meetings More information: https://www.openeuler.org/en/

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[PATCH openEuler-1.0-LTS] wifi: prevent A-MSDU attacks in mesh networks
by Zhang Yuwei 23 Jul '26

23 Jul '26

From: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> stable inclusion from stable-v6.6.99 commit ec6392061de6681148b63ee6c8744da833498cdd category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/7758 CVE: CVE-2025-27558 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 737bb912ebbe4571195c56eba557c4d7315b26fb upstream. This patch is a mitigation to prevent the A-MSDU spoofing vulnerability for mesh networks. The initial update to the IEEE 802.11 standard, in response to the FragAttacks, missed this case (CVE-2025-27558). It can be considered a variant of CVE-2020-24588 but for mesh networks. This patch tries to detect if a standard MSDU was turned into an A-MSDU by an adversary. This is done by parsing a received A-MSDU as a standard MSDU, calculating the length of the Mesh Control header, and seeing if the 6 bytes after this header equal the start of an rfc1042 header. If equal, this is a strong indication of an ongoing attack attempt. This defense was tested with mac80211_hwsim against a mesh network that uses an empty Mesh Address Extension field, i.e., when four addresses are used, and when using a 12-byte Mesh Address Extension field, i.e., when six addresses are used. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-… Cc: stable(a)vger.kernel.org Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> Link: https://patch.msgid.link/20250616004635.224344-1-Mathy.Vanhoef@kuleuven.be Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Wang Hai <wanghai38(a)huawei.com> --- net/wireless/util.c | 51 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 4e81210e5b24..4af280c1a6d4 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -623,6 +623,51 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, return frame; } +/* + * Detects if an MSDU frame was maliciously converted into an A-MSDU + * frame by an adversary. This is done by parsing the received frame + * as if it were a regular MSDU, even though the A-MSDU flag is set. + * + * For non-mesh interfaces, detection involves checking whether the + * payload, when interpreted as an MSDU, begins with a valid RFC1042 + * header. This is done by comparing the A-MSDU subheader's destination + * address to the start of the RFC1042 header. + * + * For mesh interfaces, the MSDU includes a 6-byte Mesh Control field + * and an optional variable-length Mesh Address Extension field before + * the RFC1042 header. The position of the RFC1042 header must therefore + * be calculated based on the mesh header length. + * + * Since this function intentionally parses an A-MSDU frame as an MSDU, + * it only assumes that the A-MSDU subframe header is present, and + * beyond this it performs its own bounds checks under the assumption + * that the frame is instead parsed as a non-aggregated MSDU. + */ +static bool +is_amsdu_aggregation_attack(struct ethhdr *eth, struct sk_buff *skb, + enum nl80211_iftype iftype) +{ + int offset; + + /* Non-mesh case can be directly compared */ + if (iftype != NL80211_IFTYPE_MESH_POINT) + return ether_addr_equal(eth->h_dest, rfc1042_header); + + offset = __ieee80211_get_mesh_hdrlen(eth->h_dest[0]); + if (offset == 6) { + /* Mesh case with empty address extension field */ + return ether_addr_equal(eth->h_source, rfc1042_header); + } else if (offset + ETH_ALEN <= skb->len) { + /* Mesh case with non-empty address extension field */ + u8 temp[ETH_ALEN]; + + skb_copy_bits(skb, offset, temp, ETH_ALEN); + return ether_addr_equal(temp, rfc1042_header); + } + + return false; +} + void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, const u8 *addr, enum nl80211_iftype iftype, const unsigned int extra_headroom, @@ -655,8 +700,10 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, /* the last MSDU has no padding */ if (subframe_len > remaining) goto purge; - /* mitigate A-MSDU aggregation injection attacks */ - if (ether_addr_equal(eth.h_dest, rfc1042_header)) + /* mitigate A-MSDU aggregation injection attacks, to be + * checked when processing first subframe (offset == 0). + */ + if (offset == 0 && is_amsdu_aggregation_attack(&eth, skb, iftype)) goto purge; offset += sizeof(struct ethhdr); -- 2.22.0

2 1

[PATCH openEuler-1.0-LTS] wifi: prevent A-MSDU attacks in mesh networks
by Zhang Yuwei 23 Jul '26

23 Jul '26

From: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> stable inclusion from stable-v6.6.99 commit ec6392061de6681148b63ee6c8744da833498cdd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICTWCN CVE: CVE-2025-27558 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 737bb912ebbe4571195c56eba557c4d7315b26fb upstream. This patch is a mitigation to prevent the A-MSDU spoofing vulnerability for mesh networks. The initial update to the IEEE 802.11 standard, in response to the FragAttacks, missed this case (CVE-2025-27558). It can be considered a variant of CVE-2020-24588 but for mesh networks. This patch tries to detect if a standard MSDU was turned into an A-MSDU by an adversary. This is done by parsing a received A-MSDU as a standard MSDU, calculating the length of the Mesh Control header, and seeing if the 6 bytes after this header equal the start of an rfc1042 header. If equal, this is a strong indication of an ongoing attack attempt. This defense was tested with mac80211_hwsim against a mesh network that uses an empty Mesh Address Extension field, i.e., when four addresses are used, and when using a 12-byte Mesh Address Extension field, i.e., when six addresses are used. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-… Cc: stable(a)vger.kernel.org Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> Link: https://patch.msgid.link/20250616004635.224344-1-Mathy.Vanhoef@kuleuven.be Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Wang Hai <wanghai38(a)huawei.com> --- net/wireless/util.c | 51 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 4e81210e5b24..4af280c1a6d4 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -623,6 +623,51 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, return frame; } +/* + * Detects if an MSDU frame was maliciously converted into an A-MSDU + * frame by an adversary. This is done by parsing the received frame + * as if it were a regular MSDU, even though the A-MSDU flag is set. + * + * For non-mesh interfaces, detection involves checking whether the + * payload, when interpreted as an MSDU, begins with a valid RFC1042 + * header. This is done by comparing the A-MSDU subheader's destination + * address to the start of the RFC1042 header. + * + * For mesh interfaces, the MSDU includes a 6-byte Mesh Control field + * and an optional variable-length Mesh Address Extension field before + * the RFC1042 header. The position of the RFC1042 header must therefore + * be calculated based on the mesh header length. + * + * Since this function intentionally parses an A-MSDU frame as an MSDU, + * it only assumes that the A-MSDU subframe header is present, and + * beyond this it performs its own bounds checks under the assumption + * that the frame is instead parsed as a non-aggregated MSDU. + */ +static bool +is_amsdu_aggregation_attack(struct ethhdr *eth, struct sk_buff *skb, + enum nl80211_iftype iftype) +{ + int offset; + + /* Non-mesh case can be directly compared */ + if (iftype != NL80211_IFTYPE_MESH_POINT) + return ether_addr_equal(eth->h_dest, rfc1042_header); + + offset = __ieee80211_get_mesh_hdrlen(eth->h_dest[0]); + if (offset == 6) { + /* Mesh case with empty address extension field */ + return ether_addr_equal(eth->h_source, rfc1042_header); + } else if (offset + ETH_ALEN <= skb->len) { + /* Mesh case with non-empty address extension field */ + u8 temp[ETH_ALEN]; + + skb_copy_bits(skb, offset, temp, ETH_ALEN); + return ether_addr_equal(temp, rfc1042_header); + } + + return false; +} + void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, const u8 *addr, enum nl80211_iftype iftype, const unsigned int extra_headroom, @@ -655,8 +700,10 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, /* the last MSDU has no padding */ if (subframe_len > remaining) goto purge; - /* mitigate A-MSDU aggregation injection attacks */ - if (ether_addr_equal(eth.h_dest, rfc1042_header)) + /* mitigate A-MSDU aggregation injection attacks, to be + * checked when processing first subframe (offset == 0). + */ + if (offset == 0 && is_amsdu_aggregation_attack(&eth, skb, iftype)) goto purge; offset += sizeof(struct ethhdr); -- 2.22.0

2 1

[PATCH openEuler-1.0-LTS] wifi: prevent A-MSDU attacks in mesh networks
by Zhang Yuwei 23 Jul '26

23 Jul '26

From: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> stable inclusion from stable-v6.6.99 commit ec6392061de6681148b63ee6c8744da833498cdd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICTWCN Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 737bb912ebbe4571195c56eba557c4d7315b26fb upstream. This patch is a mitigation to prevent the A-MSDU spoofing vulnerability for mesh networks. The initial update to the IEEE 802.11 standard, in response to the FragAttacks, missed this case (CVE-2025-27558). It can be considered a variant of CVE-2020-24588 but for mesh networks. This patch tries to detect if a standard MSDU was turned into an A-MSDU by an adversary. This is done by parsing a received A-MSDU as a standard MSDU, calculating the length of the Mesh Control header, and seeing if the 6 bytes after this header equal the start of an rfc1042 header. If equal, this is a strong indication of an ongoing attack attempt. This defense was tested with mac80211_hwsim against a mesh network that uses an empty Mesh Address Extension field, i.e., when four addresses are used, and when using a 12-byte Mesh Address Extension field, i.e., when six addresses are used. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-… Cc: stable(a)vger.kernel.org Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> Link: https://patch.msgid.link/20250616004635.224344-1-Mathy.Vanhoef@kuleuven.be Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Wang Hai <wanghai38(a)huawei.com> --- net/wireless/util.c | 51 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 4e81210e5b24..4af280c1a6d4 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -623,6 +623,51 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, return frame; } +/* + * Detects if an MSDU frame was maliciously converted into an A-MSDU + * frame by an adversary. This is done by parsing the received frame + * as if it were a regular MSDU, even though the A-MSDU flag is set. + * + * For non-mesh interfaces, detection involves checking whether the + * payload, when interpreted as an MSDU, begins with a valid RFC1042 + * header. This is done by comparing the A-MSDU subheader's destination + * address to the start of the RFC1042 header. + * + * For mesh interfaces, the MSDU includes a 6-byte Mesh Control field + * and an optional variable-length Mesh Address Extension field before + * the RFC1042 header. The position of the RFC1042 header must therefore + * be calculated based on the mesh header length. + * + * Since this function intentionally parses an A-MSDU frame as an MSDU, + * it only assumes that the A-MSDU subframe header is present, and + * beyond this it performs its own bounds checks under the assumption + * that the frame is instead parsed as a non-aggregated MSDU. + */ +static bool +is_amsdu_aggregation_attack(struct ethhdr *eth, struct sk_buff *skb, + enum nl80211_iftype iftype) +{ + int offset; + + /* Non-mesh case can be directly compared */ + if (iftype != NL80211_IFTYPE_MESH_POINT) + return ether_addr_equal(eth->h_dest, rfc1042_header); + + offset = __ieee80211_get_mesh_hdrlen(eth->h_dest[0]); + if (offset == 6) { + /* Mesh case with empty address extension field */ + return ether_addr_equal(eth->h_source, rfc1042_header); + } else if (offset + ETH_ALEN <= skb->len) { + /* Mesh case with non-empty address extension field */ + u8 temp[ETH_ALEN]; + + skb_copy_bits(skb, offset, temp, ETH_ALEN); + return ether_addr_equal(temp, rfc1042_header); + } + + return false; +} + void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, const u8 *addr, enum nl80211_iftype iftype, const unsigned int extra_headroom, @@ -655,8 +700,10 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, /* the last MSDU has no padding */ if (subframe_len > remaining) goto purge; - /* mitigate A-MSDU aggregation injection attacks */ - if (ether_addr_equal(eth.h_dest, rfc1042_header)) + /* mitigate A-MSDU aggregation injection attacks, to be + * checked when processing first subframe (offset == 0). + */ + if (offset == 0 && is_amsdu_aggregation_attack(&eth, skb, iftype)) goto purge; offset += sizeof(struct ethhdr); -- 2.22.0

2 1

[PATCH openEuler-1.0-LTS] wifi: prevent A-MSDU attacks in mesh networks
by Zhang Yuwei 23 Jul '26

23 Jul '26

From: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> stable inclusion from stable-v6.6.99 commit ec6392061de6681148b63ee6c8744da833498cdd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICTWCN Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 737bb912ebbe4571195c56eba557c4d7315b26fb upstream. This patch is a mitigation to prevent the A-MSDU spoofing vulnerability for mesh networks. The initial update to the IEEE 802.11 standard, in response to the FragAttacks, missed this case (CVE-2025-27558). It can be considered a variant of CVE-2020-24588 but for mesh networks. This patch tries to detect if a standard MSDU was turned into an A-MSDU by an adversary. This is done by parsing a received A-MSDU as a standard MSDU, calculating the length of the Mesh Control header, and seeing if the 6 bytes after this header equal the start of an rfc1042 header. If equal, this is a strong indication of an ongoing attack attempt. This defense was tested with mac80211_hwsim against a mesh network that uses an empty Mesh Address Extension field, i.e., when four addresses are used, and when using a 12-byte Mesh Address Extension field, i.e., when six addresses are used. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-… Cc: stable(a)vger.kernel.org Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be> Link: https://patch.msgid.link/20250616004635.224344-1-Mathy.Vanhoef@kuleuven.be Signed-off-by: Johannes Berg <johannes.berg(a)intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Wang Hai <wanghai38(a)huawei.com> --- net/wireless/util.c | 51 +++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 49 insertions(+), 2 deletions(-) diff --git a/net/wireless/util.c b/net/wireless/util.c index 4e81210e5b24..dcca1b882455 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -623,6 +623,51 @@ __ieee80211_amsdu_copy(struct sk_buff *skb, unsigned int hlen, return frame; } +/* + * Detects if an MSDU frame was maliciously converted into an A-MSDU + * frame by an adversary. This is done by parsing the received frame + * as if it were a regular MSDU, even though the A-MSDU flag is set. + * + * For non-mesh interfaces, detection involves checking whether the + * payload, when interpreted as an MSDU, begins with a valid RFC1042 + * header. This is done by comparing the A-MSDU subheader's destination + * address to the start of the RFC1042 header. + * + * For mesh interfaces, the MSDU includes a 6-byte Mesh Control field + * and an optional variable-length Mesh Address Extension field before + * the RFC1042 header. The position of the RFC1042 header must therefore + * be calculated based on the mesh header length. + * + * Since this function intentionally parses an A-MSDU frame as an MSDU, + * it only assumes that the A-MSDU subframe header is present, and + * beyond this it performs its own bounds checks under the assumption + * that the frame is instead parsed as a non-aggregated MSDU. + */ +static bool +is_amsdu_aggregation_attack(struct ethhdr *eth, struct sk_buff *skb, + enum nl80211_iftype iftype) +{ + int offset; + + /* Non-mesh case can be directly compared */ + if (iftype != NL80211_IFTYPE_MESH_POINT) + return ether_addr_equal(eth->h_dest, rfc1042_header); + + offset = __ieee80211_get_mesh_hdrlen(eth->h_dest[0]); + if (offset == 6) { + /* Mesh case with empty address extension field */ + return ether_addr_equal(eth->h_source, rfc1042_header); + } else if (offset + ETH_ALEN <= skb->len) { + /* Mesh case with non-empty address extension field */ + u8 temp[ETH_ALEN]; + + skb_copy_bits(skb, offset, temp, ETH_ALEN); + return ether_addr_equal(temp, rfc1042_header); + } + + return false; +} + void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, const u8 *addr, enum nl80211_iftype iftype, const unsigned int extra_headroom, @@ -655,8 +700,10 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list, /* the last MSDU has no padding */ if (subframe_len > remaining) goto purge; - /* mitigate A-MSDU aggregation injection attacks */ - if (ether_addr_equal(eth.h_dest, rfc1042_header)) + /* mitigate A-MSDU aggregation injection attacks, to be + * checked when processing first subframe (offset == 0). + */ + if (offset == 0 && is_amsdu_aggregation_attack(&hdr.eth, skb, iftype)) goto purge; offset += sizeof(struct ethhdr); -- 2.22.0

2 1