From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793212328; b=kj9YF+3ipZmoCr7QHSou0CbUMeT3srDN9qaw8EGXzGZAnQk1C7BlDPPAZi1sqCOMgNOe Z2rQW/NxFUS5aL551Mu9AmZEbJneQR0O2VqZ7HkSwa7I0Hh0Rvp77+oPua433r2Qs0+eq qxinChuUdvdn+TDrGsM/7OhVexJVdj1RlS3kuy9F/tFX3gT5wVKosFGHDSP5EhQLUPNHE MMUA73nL+bSl/5YvmAcnDO0XoijysFT6jcwhzXp521pUvFrZrKW+azDTlZQS6P5iSSm+d 6oI7zlUh3yoAOzMESopdUW3t4+mWPc4zC6C8McmYHYOFEFtIUv3f6isUKbnH+e+Au7g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793212328; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=uINXdw0QupFwlQgdf98UhTDqVCkZjSu5Dg6DqkgUKUc=; b=GRrv6XYa5aguBjHoNztNxtOz1mUQiP/FsO6JEAJAO9yobNboFGgeQvO7coAtZywQVfYR y+sThng/kHX1fS+ZY8NfaV7cL5+rJodzuvSR8NDle9it8wH8AMBx9SO5fVqo/llpVZ3U7 OccTGHoE/j+IloyqSNBD9ZSIvjyNfOSqor1dnIGpD/raxuZS7040pHFppk2MrWfjWmRH+ 9A/piiYIh9ht29RIoc0RdmtDXSGVpQz72Gc+C+WcVk/cjSUmUEhcau0DHHl7rWu7ru54c NWo96eTSTrI/KzlOjZcMCRg535GR5s5i7F/PnboyKrFU4LU+QlWZh5cx9xK0gnQTPbA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=IWpYT3f0; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ACA9D606A31A; Wed, 28 Oct 2026 18:32:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=IWpYT3f0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id E48971F01825; Wed, 28 Oct 2026 18:32:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793212327; bh=uINXdw0QupFwlQgdf98UhTDqVCkZjSu5Dg6DqkgUKUc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IWpYT3f0YNXrMYPR+9QnsjYveI8v4VJvpz4MmcD+MBrInYr/1LzczIyJxab8GL007 bFwKmdzDuqJgEhT87YXGl9DnRiwIT/aDUMonRiAndVSjCaLl8cVfiG0/Yu7P0VuFhk aSs5155Q5HU15X0C3h/8bOk/TUkujsA2bmm0AWSQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qing Ming , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 0061/1887] gtp: serialize PDP context updates Date: Wed, 28 Oct 2026 17:35:57 +0100 Message-ID: <20261028170500.616074295@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qing Ming [ Upstream commit 498386b6d402737db1e2eeed4c385acbf0ef9e34 ] PDP contexts can be deleted through GTP_CMD_DELPDP or while the GTP network device is being unregistered. The latter is serialized by RTNL, but the generic-netlink delete path only holds RCU. Running both paths concurrently can therefore make both paths delete the same PDP context. The issue was found through static analysis and reproduced on a KASAN-enabled kernel by a simple two-thread program racing GTP_CMD_DELPDP against RTM_DELLINK: Oops: general protection fault, probably for non-canonical address KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127] RIP: gtp_genl_del_pdp+0x1c1/0x420 [gtp] RBP: dead000000000122 The second deletion dereferenced the poisoned hlist pprev pointer. Serialize gtp_pdp_add(), gtp_genl_del_pdp(), and gtp_dellink() with a shared mutex. Keep the mutex held until the final use of a PDP context in the NEWPDP path, and keep the RCU read-side section around the complete PDP context use in the DELPDP path. Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Cc: stable@vger.kernel.org Signed-off-by: Qing Ming Link: https://patch.msgid.link/20260818150000.7670-1-a0yami@mailbox.org Signed-off-by: Jakub Kicinski [ adapted the locking changes to the older IPv4-only PDP context API and omitted the absent IPv6 lookup hunk. ] Signed-off-by: Sasha Levin --- drivers/net/gtp.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 0817ff58b8dab..501dbfa917408 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -12,6 +12,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -92,6 +93,7 @@ struct gtp_net { }; static u32 gtp_h_initval; +static DEFINE_MUTEX(gtp_pdp_lock); static struct genl_family gtp_genl_family; @@ -129,7 +131,8 @@ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_tid) { + hlist_for_each_entry_rcu(pdp, head, hlist_tid, + lockdep_is_held(>p_pdp_lock)) { if (pdp->gtp_version == GTP_V0 && pdp->u.v0.tid == tid) return pdp; @@ -145,7 +148,8 @@ static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_tid) { + hlist_for_each_entry_rcu(pdp, head, hlist_tid, + lockdep_is_held(>p_pdp_lock)) { if (pdp->gtp_version == GTP_V1 && pdp->u.v1.i_tei == tid) return pdp; @@ -161,7 +165,8 @@ static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; - hlist_for_each_entry_rcu(pdp, head, hlist_addr) { + hlist_for_each_entry_rcu(pdp, head, hlist_addr, + lockdep_is_held(>p_pdp_lock)) { if (pdp->af == AF_INET && pdp->ms_addr_ip4.s_addr == ms_addr) return pdp; @@ -1120,9 +1125,11 @@ static void gtp_dellink(struct net_device *dev, struct list_head *head) struct pdp_ctx *pctx; int i; + mutex_lock(>p_pdp_lock); for (i = 0; i < gtp->hash_size; i++) hlist_for_each_entry_safe(pctx, next, >p->tid_hash[i], hlist_tid) pdp_context_delete(pctx); + mutex_unlock(>p_pdp_lock); list_del(>p->list); unregister_netdevice_queue(dev, head); @@ -1507,6 +1514,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) goto out_unlock; } + mutex_lock(>p_pdp_lock); pctx = gtp_pdp_add(gtp, sk, info); if (IS_ERR(pctx)) { err = PTR_ERR(pctx); @@ -1514,6 +1522,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL); err = 0; } + mutex_unlock(>p_pdp_lock); out_unlock: rtnl_unlock(); @@ -1568,6 +1577,8 @@ static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) if (!info->attrs[GTPA_VERSION]) return -EINVAL; + mutex_lock(>p_pdp_lock); + rcu_read_lock(); pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); @@ -1588,6 +1599,7 @@ static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) out_unlock: rcu_read_unlock(); + mutex_unlock(>p_pdp_lock); return err; } -- 2.53.0