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 0045A1F5439; Tue, 21 Jan 2025 17:59:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482353; cv=none; b=IcDnaBhJ9JfdlFQArSUCuE2kRAie8X9Prs/2gfdwgElPW9xTX6ZUb0Mj51w643qLr0v2WEx6Ntiw/agzlXWl1bK+ZK4f/kgUkhjAopCq4pa8RurjXlgwNspEjCXLU70et5HJUNXVe3rCJZ3yTbZrRdCWzuNlrYYbOGwkDXthGeU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737482353; c=relaxed/simple; bh=9XLfaPKHM4xXe9FpU6Xerk2Lr/tWsVd+Z5wFKY8QK7E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KmyjxewCAh761mxK1eGHpmFa7IQwbwY/7iMwyhjzBqJ9TnEWH/7/KsdhaYRkGfMFrZxvYzMiOYxb5Lc2JFT3wavhbykVRSXwuL+aYurzRwuf/WUhbnNfa/WMz0Ir4Zfrr7t8MC0U60wcKiouwmxFZ592yENoDJaev8gHIb/C84o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iRtZ727S; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iRtZ727S" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D9F3C4CEE0; Tue, 21 Jan 2025 17:59:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1737482352; bh=9XLfaPKHM4xXe9FpU6Xerk2Lr/tWsVd+Z5wFKY8QK7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iRtZ727S1MwZVLiwtflNILHLMdNvUN7NgxtJ+QFZEq10Ply/iXVQzd3vra4FwRwPM FmJz7UPJ/SXnAR8SXg832BX5l00rlhUbkWNl97DfEKhvdCiFCy9k2l1NTj9s8n6TUr A3EMw9zayP4r9wii1EipDOeLcdkgl5woDnxnmzbk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jay Shin , "Paulo Alcantara (Red Hat)" , Steve French , Sasha Levin Subject: [PATCH 6.12 048/122] smb: client: fix double free of TCP_Server_Info::hostname Date: Tue, 21 Jan 2025 18:51:36 +0100 Message-ID: <20250121174534.835798555@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250121174532.991109301@linuxfoundation.org> References: <20250121174532.991109301@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paulo Alcantara [ Upstream commit fa2f9906a7b333ba757a7dbae0713d8a5396186e ] When shutting down the server in cifs_put_tcp_session(), cifsd thread might be reconnecting to multiple DFS targets before it realizes it should exit the loop, so @server->hostname can't be freed as long as cifsd thread isn't done. Otherwise the following can happen: RIP: 0010:__slab_free+0x223/0x3c0 Code: 5e 41 5f c3 cc cc cc cc 4c 89 de 4c 89 cf 44 89 44 24 08 4c 89 1c 24 e8 fb cf 8e 00 44 8b 44 24 08 4c 8b 1c 24 e9 5f fe ff ff <0f> 0b 41 f7 45 08 00 0d 21 00 0f 85 2d ff ff ff e9 1f ff ff ff 80 RSP: 0018:ffffb26180dbfd08 EFLAGS: 00010246 RAX: ffff8ea34728e510 RBX: ffff8ea34728e500 RCX: 0000000000800068 RDX: 0000000000800068 RSI: 0000000000000000 RDI: ffff8ea340042400 RBP: ffffe112041ca380 R08: 0000000000000001 R09: 0000000000000000 R10: 6170732e31303000 R11: 70726f632e786563 R12: ffff8ea34728e500 R13: ffff8ea340042400 R14: ffff8ea34728e500 R15: 0000000000800068 FS: 0000000000000000(0000) GS:ffff8ea66fd80000(0000) 000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc25376080 CR3: 000000012a2ba001 CR4: PKRU: 55555554 Call Trace: ? show_trace_log_lvl+0x1c4/0x2df ? show_trace_log_lvl+0x1c4/0x2df ? __reconnect_target_unlocked+0x3e/0x160 [cifs] ? __die_body.cold+0x8/0xd ? die+0x2b/0x50 ? do_trap+0xce/0x120 ? __slab_free+0x223/0x3c0 ? do_error_trap+0x65/0x80 ? __slab_free+0x223/0x3c0 ? exc_invalid_op+0x4e/0x70 ? __slab_free+0x223/0x3c0 ? asm_exc_invalid_op+0x16/0x20 ? __slab_free+0x223/0x3c0 ? extract_hostname+0x5c/0xa0 [cifs] ? extract_hostname+0x5c/0xa0 [cifs] ? __kmalloc+0x4b/0x140 __reconnect_target_unlocked+0x3e/0x160 [cifs] reconnect_dfs_server+0x145/0x430 [cifs] cifs_handle_standard+0x1ad/0x1d0 [cifs] cifs_demultiplex_thread+0x592/0x730 [cifs] ? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs] kthread+0xdd/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x29/0x50 Fixes: 7be3248f3139 ("cifs: To match file servers, make sure the server hostname matches") Reported-by: Jay Shin Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/client/connect.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index fe40152b915d8..fb51cdf552061 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1044,6 +1044,7 @@ clean_demultiplex_info(struct TCP_Server_Info *server) /* Release netns reference for this server. */ put_net(cifs_net_ns(server)); kfree(server->leaf_fullpath); + kfree(server->hostname); kfree(server); length = atomic_dec_return(&tcpSesAllocCount); @@ -1670,8 +1671,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) kfree_sensitive(server->session_key.response); server->session_key.response = NULL; server->session_key.len = 0; - kfree(server->hostname); - server->hostname = NULL; task = xchg(&server->tsk, NULL); if (task) -- 2.39.5