| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2023-52701: net: use a bounce buffer for copying skb->mark |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: use a bounce buffer for copying skb->mark |
| |
| syzbot found arm64 builds would crash in sock_recv_mark() |
| when CONFIG_HARDENED_USERCOPY=y |
| |
| x86 and powerpc are not detecting the issue because |
| they define user_access_begin. |
| This will be handled in a different patch, |
| because a check_object_size() is missing. |
| |
| Only data from skb->cb[] can be copied directly to/from user space, |
| as explained in commit 79a8a642bf05 ("net: Whitelist |
| the skbuff_head_cache "cb" field") |
| |
| syzbot report was: |
| usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_head_cache' (offset 168, size 4)! |
| ------------[ cut here ]------------ |
| kernel BUG at mm/usercopy.c:102 ! |
| Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP |
| Modules linked in: |
| CPU: 0 PID: 4410 Comm: syz-executor533 Not tainted 6.2.0-rc7-syzkaller-17907-g2d3827b3f393 #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 |
| pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) |
| pc : usercopy_abort+0x90/0x94 mm/usercopy.c:90 |
| lr : usercopy_abort+0x90/0x94 mm/usercopy.c:90 |
| sp : ffff80000fb9b9a0 |
| x29: ffff80000fb9b9b0 x28: ffff0000c6073400 x27: 0000000020001a00 |
| x26: 0000000000000014 x25: ffff80000cf52000 x24: fffffc0000000000 |
| x23: 05ffc00000000200 x22: fffffc000324bf80 x21: ffff0000c92fe1a8 |
| x20: 0000000000000001 x19: 0000000000000004 x18: 0000000000000000 |
| x17: 656a626f2042554c x16: ffff0000c6073dd0 x15: ffff80000dbd2118 |
| x14: ffff0000c6073400 x13: 00000000ffffffff x12: ffff0000c6073400 |
| x11: ff808000081bbb4c x10: 0000000000000000 x9 : 7b0572d7cc0ccf00 |
| x8 : 7b0572d7cc0ccf00 x7 : ffff80000bf650d4 x6 : 0000000000000000 |
| x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000 |
| x2 : ffff0001fefbff08 x1 : 0000000100000000 x0 : 000000000000006c |
| Call trace: |
| usercopy_abort+0x90/0x94 mm/usercopy.c:90 |
| __check_heap_object+0xa8/0x100 mm/slub.c:4761 |
| check_heap_object mm/usercopy.c:196 [inline] |
| __check_object_size+0x208/0x6b8 mm/usercopy.c:251 |
| check_object_size include/linux/thread_info.h:199 [inline] |
| __copy_to_user include/linux/uaccess.h:115 [inline] |
| put_cmsg+0x408/0x464 net/core/scm.c:238 |
| sock_recv_mark net/socket.c:975 [inline] |
| __sock_recv_cmsgs+0x1fc/0x248 net/socket.c:984 |
| sock_recv_cmsgs include/net/sock.h:2728 [inline] |
| packet_recvmsg+0x2d8/0x678 net/packet/af_packet.c:3482 |
| ____sys_recvmsg+0x110/0x3a0 |
| ___sys_recvmsg net/socket.c:2737 [inline] |
| __sys_recvmsg+0x194/0x210 net/socket.c:2767 |
| __do_sys_recvmsg net/socket.c:2777 [inline] |
| __se_sys_recvmsg net/socket.c:2774 [inline] |
| __arm64_sys_recvmsg+0x2c/0x3c net/socket.c:2774 |
| __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] |
| invoke_syscall+0x64/0x178 arch/arm64/kernel/syscall.c:52 |
| el0_svc_common+0xbc/0x180 arch/arm64/kernel/syscall.c:142 |
| do_el0_svc+0x48/0x110 arch/arm64/kernel/syscall.c:193 |
| el0_svc+0x58/0x14c arch/arm64/kernel/entry-common.c:637 |
| el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 |
| el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 |
| Code: 91388800 aa0903e1 f90003e8 94e6d752 (d4210000) |
| |
| The Linux kernel CVE team has assigned CVE-2023-52701 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.19 with commit 6fd1d51cfa253b5ee7dae18d7cf1df830e9b6137 and fixed in 6.1.13 with commit 863a7de987f02a901bf215509276a7de0370e0f9 |
| Issue introduced in 5.19 with commit 6fd1d51cfa253b5ee7dae18d7cf1df830e9b6137 and fixed in 6.2 with commit 2558b8039d059342197610498c8749ad294adee5 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2023-52701 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/socket.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/863a7de987f02a901bf215509276a7de0370e0f9 |
| https://git.kernel.org/stable/c/2558b8039d059342197610498c8749ad294adee5 |
