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 5756318654 for ; Wed, 20 Sep 2023 11:47:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF232C433C7; Wed, 20 Sep 2023 11:47:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695210464; bh=m1WJs3oGp/e7o7G+jHQqRO3HPZsb6KrR/EU+Ms3lvbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1E2xkfwwqxVhaxThUdvW4K8AeejkyGjPOX8u6/2hOiqk1vxfgd6K/ypLxtZ+aSc6+ qphmPV6RnG3gcPcUdsV6V1Sa5zlhPG/8rXs5Uphpn4uew9PGpovYwEDoyOn71TlhwJ EVUVJ1z97cJESeqBr8iWw+5wWShXKAwzLGRTu45w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Breno Leitao , Jens Axboe , Sasha Levin Subject: [PATCH 6.5 086/211] io_uring: annotate the struct io_kiocb slab for appropriate user copy Date: Wed, 20 Sep 2023 13:28:50 +0200 Message-ID: <20230920112848.480893484@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112845.859868994@linuxfoundation.org> References: <20230920112845.859868994@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jens Axboe [ Upstream commit b97f96e22f051d59d07a527dbd7d90408b661ca8 ] When compiling the kernel with clang and having HARDENED_USERCOPY enabled, the liburing openat2.t test case fails during request setup: usercopy: Kernel memory overwrite attempt detected to SLUB object 'io_kiocb' (offset 24, size 24)! ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:102! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 3 PID: 413 Comm: openat2.t Tainted: G N 6.4.3-g6995e2de6891-dirty #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 RIP: 0010:usercopy_abort+0x84/0x90 Code: ce 49 89 ce 48 c7 c3 68 48 98 82 48 0f 44 de 48 c7 c7 56 c6 94 82 4c 89 de 48 89 c1 41 52 41 56 53 e8 e0 51 c5 00 48 83 c4 18 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 41 57 41 56 RSP: 0018:ffffc900016b3da0 EFLAGS: 00010296 RAX: 0000000000000062 RBX: ffffffff82984868 RCX: 4e9b661ac6275b00 RDX: ffff8881b90ec580 RSI: ffffffff82949a64 RDI: 00000000ffffffff RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900016b3c88 R11: ffffc900016b3c30 R12: 00007ffe549659e0 R13: ffff888119014000 R14: 0000000000000018 R15: 0000000000000018 FS: 00007f862e3ca680(0000) GS:ffff8881b90c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005571483542a8 CR3: 0000000118c11000 CR4: 00000000003506e0 Call Trace: ? __die_body+0x63/0xb0 ? die+0x9d/0xc0 ? do_trap+0xa7/0x180 ? usercopy_abort+0x84/0x90 ? do_error_trap+0xc6/0x110 ? usercopy_abort+0x84/0x90 ? handle_invalid_op+0x2c/0x40 ? usercopy_abort+0x84/0x90 ? exc_invalid_op+0x2f/0x40 ? asm_exc_invalid_op+0x16/0x20 ? usercopy_abort+0x84/0x90 __check_heap_object+0xe2/0x110 __check_object_size+0x142/0x3d0 io_openat2_prep+0x68/0x140 io_submit_sqes+0x28a/0x680 __se_sys_io_uring_enter+0x120/0x580 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x55714834de26 Code: ca 01 0f b6 82 d0 00 00 00 8b ba cc 00 00 00 45 31 c0 31 d2 41 b9 08 00 00 00 83 e0 01 c1 e0 04 41 09 c2 b8 aa 01 00 00 0f 05 66 0f 1f 84 00 00 00 00 00 89 30 eb 89 0f 1f 40 00 8b 00 a8 06 RSP: 002b:00007ffe549659c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007ffe54965a50 RCX: 000055714834de26 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000246 R12: 000055714834f057 R13: 00007ffe54965a50 R14: 0000000000000001 R15: 0000557148351dd8 Modules linked in: ---[ end trace 0000000000000000 ]--- when it tries to copy struct open_how from userspace into the per-command space in the io_kiocb. There's nothing wrong with the copy, but we're missing the appropriate annotations for allowing user copies to/from the io_kiocb slab. Allow copies in the per-command area, which is from the 'file' pointer to when 'opcode' starts. We do have existing user copies there, but they are not all annotated like the one that openat2_prep() uses, copy_struct_from_user(). But in practice opcodes should be allowed to copy data into their per-command area in the io_kiocb. Reported-by: Breno Leitao Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- io_uring/io_uring.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 4e9217c1eb2e0..a1562f2cf3f3c 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -4628,8 +4628,20 @@ static int __init io_uring_init(void) io_uring_optable_init(); - req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC | - SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU); + /* + * Allow user copy in the per-command field, which starts after the + * file in io_kiocb and until the opcode field. The openat2 handling + * requires copying in user memory into the io_kiocb object in that + * range, and HARDENED_USERCOPY will complain if we haven't + * correctly annotated this range. + */ + req_cachep = kmem_cache_create_usercopy("io_kiocb", + sizeof(struct io_kiocb), 0, + SLAB_HWCACHE_ALIGN | SLAB_PANIC | + SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU, + offsetof(struct io_kiocb, cmd.data), + sizeof_field(struct io_kiocb, cmd.data), NULL); + return 0; }; __initcall(io_uring_init); -- 2.40.1