From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6DAEB3173F; Fri, 24 Nov 2023 18:57:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uKul6gg6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F00B0C433C7; Fri, 24 Nov 2023 18:57:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700852271; bh=JxPxlqIc1AKCUGcszwUVHISmQ1KW3jNjO32z5dcwuBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uKul6gg6PURrCC+K+qHCDGvVpJL29XenRPCXtbVglU7WrADKecj7mtLnSIvFTS1kO F2e1Un/qjJH82aV0UP1z87b/c9tS7C1hn5hlKPiyGIwH3hfqGRpIyjGK5KRWz9+tJ0 JngS79sdVUnOEgAVtNTUhLJMfyRCxt2GCLdNzvD8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Paulo Alcantara (SUSE)" , Steve French Subject: [PATCH 6.1 271/372] smb: client: fix use-after-free bug in cifs_debug_data_proc_show() Date: Fri, 24 Nov 2023 17:50:58 +0000 Message-ID: <20231124172019.499084165@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124172010.413667921@linuxfoundation.org> References: <20231124172010.413667921@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara commit d328c09ee9f15ee5a26431f5aad7c9239fa85e62 upstream. Skip SMB sessions that are being teared down (e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show() to avoid use-after-free in @ses. This fixes the following GPF when reading from /proc/fs/cifs/DebugData while mounting and umounting [ 816.251274] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI ... [ 816.260138] Call Trace: [ 816.260329] [ 816.260499] ? die_addr+0x36/0x90 [ 816.260762] ? exc_general_protection+0x1b3/0x410 [ 816.261126] ? asm_exc_general_protection+0x26/0x30 [ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs] [ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs] [ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs] [ 816.262689] ? seq_read_iter+0x379/0x470 [ 816.262995] seq_read_iter+0x118/0x470 [ 816.263291] proc_reg_read_iter+0x53/0x90 [ 816.263596] ? srso_alias_return_thunk+0x5/0x7f [ 816.263945] vfs_read+0x201/0x350 [ 816.264211] ksys_read+0x75/0x100 [ 816.264472] do_syscall_64+0x3f/0x90 [ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 816.265135] RIP: 0033:0x7fd5e669d381 Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/cifs_debug.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/smb/client/cifs_debug.c +++ b/fs/smb/client/cifs_debug.c @@ -380,6 +380,11 @@ skip_rdma: seq_printf(m, "\n\n\tSessions: "); i = 0; list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_EXITING) { + spin_unlock(&ses->ses_lock); + continue; + } i++; if ((ses->serverDomain == NULL) || (ses->serverOS == NULL) || @@ -400,6 +405,7 @@ skip_rdma: ses->ses_count, ses->serverOS, ses->serverNOS, ses->capabilities, ses->ses_status); } + spin_unlock(&ses->ses_lock); seq_printf(m, "\n\tSecurity type: %s ", get_security_type_str(server->ops->select_sectype(server, ses->sectype)));