KASAN: slab-out-of-bounds Read in rds_cong_queue_updates (2)
Hello, syzbot found the following crash on: HEAD commit:0026129c8629 rhashtable: add restart routine in rhashtable.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=10b7ced040 kernel config: https://syzkaller.appspot.com/x/.config?x=b88de6eac8694da6 dashboard link: https://syzkaller.appspot.com/bug?extid=0570fef57a5e020bdc87 compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0570fef57a5e020bd...@syzkaller.appspotmail.com == BUG: KASAN: slab-out-of-bounds in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: slab-out-of-bounds in refcount_read include/linux/refcount.h:42 [inline] BUG: KASAN: slab-out-of-bounds in check_net include/net/net_namespace.h:237 [inline] BUG: KASAN: slab-out-of-bounds in rds_destroy_pending net/rds/rds.h:902 [inline] BUG: KASAN: slab-out-of-bounds in rds_cong_queue_updates+0x25d/0x5b0 net/rds/cong.c:226 Read of size 4 at addr 88019f8ec204 by task syz-executor1/27023 CPU: 0 PID: 27023 Comm: syz-executor1 Not tainted 4.18.0-rc3+ #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_read include/linux/refcount.h:42 [inline] check_net include/net/net_namespace.h:237 [inline] rds_destroy_pending net/rds/rds.h:902 [inline] rds_cong_queue_updates+0x25d/0x5b0 net/rds/cong.c:226 rds_recv_rcvbuf_delta.part.3+0x332/0x3e0 net/rds/recv.c:123 rds_recv_rcvbuf_delta net/rds/recv.c:382 [inline] rds_recv_incoming+0x85a/0x1320 net/rds/recv.c:382 netlink: 'syz-executor2': attribute type 18 has an invalid length. rds_loop_xmit+0x16a/0x340 net/rds/loop.c:95 rds_send_xmit+0x1343/0x29c0 net/rds/send.c:355 netlink: 180 bytes leftover after parsing attributes in process `syz-executor5'. rds_sendmsg+0x229e/0x2a40 net/rds/send.c:1243 netlink: 180 bytes leftover after parsing attributes in process `syz-executor5'. sock_sendmsg_nosec net/socket.c:641 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:651 __sys_sendto+0x3d7/0x670 net/socket.c:1797 __do_sys_sendto net/socket.c:1809 [inline] __se_sys_sendto net/socket.c:1805 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1805 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:7fd164b21c68 EFLAGS: 0246 ORIG_RAX: 002c RAX: ffda RBX: 7fd164b226d4 RCX: 00455e29 RDX: 0481 RSI: 2000 RDI: 0013 RBP: 0072bea0 R08: 2069affb R09: 0010 R10: R11: 0246 R12: R13: 004c14f2 R14: 004d1a08 R15: Allocated by task 26052: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 getname_flags+0xd0/0x5a0 fs/namei.c:140 getname+0x19/0x20 fs/namei.c:211 do_sys_open+0x3a2/0x760 fs/open.c:1095 __do_sys_open fs/open.c:1119 [inline] __se_sys_open fs/open.c:1114 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1114 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26052: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 putname+0xf2/0x130 fs/namei.c:261 do_sys_open+0x569/0x760 fs/open.c:1110 __do_sys_open fs/open.c:1119 [inline] __se_sys_open fs/open.c:1114 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1114 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at 88019f8ec280 which belongs to the cache names_cache of size 4096 The buggy address is located 124 bytes to the left of 4096-byte region [88019f8ec280, 88019f8ed280) The buggy add
Re: KASAN: slab-out-of-bounds Read in rds_cong_queue_updates
On Mon, Mar 19, 2018 at 9:37 AM, Sowmini Varadhan wrote: > On (03/19/18 09:29), Dmitry Vyukov wrote: >> >> This looks the same as: >> >> #syz dup: KASAN: use-after-free Read in rds_cong_queue_updates > > correct, seems like the rds_destroy_pending() fixes did not seal > this race condition. I need to look at this more carefully to see > what race I missed.. no easy answer here, I am afraid. Hi Sowmini, What fix do you mean? syzbot does not know about any fixes for any of the bugs as far as I see. So maybe your fix actually fixed it, but it's not in upstream yes, and syzbot still finds this in upstream. We tell syzbot about fixes (with Reported-by tags or "#syz fix" email commands) to be able to later make sense of the state of the bugs.
Re: KASAN: slab-out-of-bounds Read in rds_cong_queue_updates
On (03/19/18 09:29), Dmitry Vyukov wrote: > > This looks the same as: > > #syz dup: KASAN: use-after-free Read in rds_cong_queue_updates correct, seems like the rds_destroy_pending() fixes did not seal this race condition. I need to look at this more carefully to see what race I missed.. no easy answer here, I am afraid. --Sowmini
Re: KASAN: slab-out-of-bounds Read in rds_cong_queue_updates
On Thu, Feb 22, 2018 at 12:49 PM, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 79c0ef3e85c015b0921a8fd5dd539d1480e9cd6c (Mon Feb 19 19:58:19 2018 +) > Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > > So far this crash happened 28 times on > https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/master. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > user-space arch: i386 This looks the same as: #syz dup: KASAN: use-after-free Read in rds_cong_queue_updates > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+80c06fb3aabfa386b...@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > == > BUG: KASAN: slab-out-of-bounds in __read_once_size > include/linux/compiler.h:183 [inline] > BUG: KASAN: slab-out-of-bounds in atomic_read > arch/x86/include/asm/atomic.h:27 [inline] > BUG: KASAN: slab-out-of-bounds in refcount_read include/linux/refcount.h:42 > [inline] > BUG: KASAN: slab-out-of-bounds in check_net include/net/net_namespace.h:228 > [inline] > BUG: KASAN: slab-out-of-bounds in rds_destroy_pending net/rds/rds.h:868 > [inline] > BUG: KASAN: slab-out-of-bounds in rds_cong_queue_updates+0x4d2/0x4f0 > net/rds/cong.c:226 > Read of size 4 at addr 8801d31a0044 by task syz-executor1/21851 > > CPU: 1 PID: 21851 Comm: syz-executor1 Not tainted 4.16.0-rc2+ #232 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report+0x23b/0x360 mm/kasan/report.c:412 > __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 > __read_once_size include/linux/compiler.h:183 [inline] > atomic_read arch/x86/include/asm/atomic.h:27 [inline] > refcount_read include/linux/refcount.h:42 [inline] > check_net include/net/net_namespace.h:228 [inline] > rds_destroy_pending net/rds/rds.h:868 [inline] > rds_cong_queue_updates+0x4d2/0x4f0 net/rds/cong.c:226 > rds_recv_rcvbuf_delta.part.2+0x289/0x320 net/rds/recv.c:118 > rds_recv_rcvbuf_delta net/rds/recv.c:377 [inline] > rds_recv_incoming+0xeb4/0x11d0 net/rds/recv.c:377 > rds_loop_xmit+0x149/0x320 net/rds/loop.c:82 > rds_send_xmit+0xbcc/0x26b0 net/rds/send.c:355 > rds_sendmsg+0x1fcb/0x2390 net/rds/send.c:1208 > sock_sendmsg_nosec net/socket.c:630 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:640 > SYSC_sendto+0x361/0x5c0 net/socket.c:1747 > SyS_sendto+0x40/0x50 net/socket.c:1715 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > RIP: 0023:0xf7f9ac79 > RSP: 002b:f779609c EFLAGS: 0286 ORIG_RAX: 0171 > RAX: ffda RBX: 0013 RCX: 20f7db7f > RDX: 0481 RSI: RDI: 2069affb > RBP: 0010 R08: R09: > R10: R11: R12: > R13: R14: R15: > > Allocated by task 20583: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 > kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541 > getname_flags+0xcb/0x580 fs/namei.c:138 > user_path_at_empty+0x2d/0x50 fs/namei.c:2568 > user_path_at include/linux/namei.h:57 [inline] > SYSC_chdir fs/open.c:440 [inline] > SyS_chdir+0xb0/0x200 fs/open.c:434 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > > Freed by task 20583: > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 > __cache_free mm/slab.c:3485 [inline] > kmem_cache_free+0x83/0x2a0 mm/slab.c:3743 > putname+0xee/0x130 fs/namei.c:258 > filename_lookup+0x315/0x500 fs/namei.c:2323 > user_path_at_empty+0x40/0x50 fs/namei.c:2568 > user_path_at include/linux/namei.h:57 [inline] > SYSC_chdir fs/open.c:440 [inline] > SyS_chdir+0xb0/0x200 fs/open.c:434 > do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] > do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
