On Sun, Mar 25, 2018 at 05:01:03PM -0700, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > bcfc1f4554662d8f2429ac8bd96064a59c149754 (Sat Mar 24 16:50:12 2018 +0000) > Merge tag 'pinctrl-v4.16-3' of > git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=db1c219466daac1083df > > So far this crash happened 4 times on upstream. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5164223906709504 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=5357898477600768 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=5549124782915584 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-5034017172441945317 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+db1c219466daac1083df@xxxxxxxxxxxxxxxxxxxxxxxxx > 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. > > IPVS: ftp: loaded support on port[0] = 21 > IPVS: ftp: loaded support on port[0] = 21 > IPVS: ftp: loaded support on port[0] = 21 > ================================================================== > BUG: KASAN: use-after-free in __list_add_valid+0xc6/0xd0 lib/list_debug.c:26 > IPVS: ftp: loaded support on port[0] = 21 > Read of size 8 at addr ffff8801ca8adcd8 by task syzkaller401155/4288 > > CPU: 0 PID: 4288 Comm: syzkaller401155 Not tainted 4.16.0-rc6+ #365 > 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+0x194/0x24d lib/dump_stack.c:53 > print_address_description+0x73/0x250 mm/kasan/report.c:256 > IPVS: ftp: loaded support on port[0] = 21 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report+0x23c/0x360 mm/kasan/report.c:412 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > __list_add_valid+0xc6/0xd0 lib/list_debug.c:26 > __list_add include/linux/list.h:60 [inline] > list_add_tail include/linux/list.h:93 [inline] > cma_listen_on_all drivers/infiniband/core/cma.c:2309 [inline] > rdma_listen+0x581/0x8e0 drivers/infiniband/core/cma.c:3333 > ucma_listen+0x172/0x1f0 drivers/infiniband/core/ucma.c:1074 > ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649 > IPVS: ftp: loaded support on port[0] = 21 > __vfs_write+0xef/0x970 fs/read_write.c:480 > IPVS: ftp: loaded support on port[0] = 21 > vfs_write+0x189/0x510 fs/read_write.c:544 > SYSC_write fs/read_write.c:589 [inline] > SyS_write+0xef/0x220 fs/read_write.c:581 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > IPVS: ftp: loaded support on port[0] = 21 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x44a9e9 > RSP: 002b:00007f94303f3da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00000000006e29fc RCX: 000000000044a9e9 > RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000004 > RBP: 00000000006e29f8 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 2f646e6162696e69 > R13: 666e692f7665642f R14: 7073642f7665642f R15: 0000000000000009 > > Allocated by task 4284: > 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 > kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3607 > kmalloc include/linux/slab.h:512 [inline] > kzalloc include/linux/slab.h:701 [inline] > rdma_create_id+0xd0/0x630 drivers/infiniband/core/cma.c:787 > ucma_create_id+0x35f/0x920 drivers/infiniband/core/ucma.c:480 > ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649 > __vfs_write+0xef/0x970 fs/read_write.c:480 > vfs_write+0x189/0x510 fs/read_write.c:544 > SYSC_write fs/read_write.c:589 [inline] > SyS_write+0xef/0x220 fs/read_write.c:581 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > Freed by task 4284: > 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] > kfree+0xd9/0x260 mm/slab.c:3800 > rdma_destroy_id+0x821/0xda0 drivers/infiniband/core/cma.c:1691 > ucma_close+0x100/0x2f0 drivers/infiniband/core/ucma.c:1728 > __fput+0x327/0x7e0 fs/file_table.c:209 > ____fput+0x15/0x20 fs/file_table.c:243 > task_work_run+0x199/0x270 kernel/task_work.c:113 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x9bb/0x1ad0 kernel/exit.c:865 > do_group_exit+0x149/0x400 kernel/exit.c:968 > get_signal+0x73a/0x16d0 kernel/signal.c:2469 > do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 > exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > > The buggy address belongs to the object at ffff8801ca8adb00 > which belongs to the cache kmalloc-1024 of size 1024 > The buggy address is located 472 bytes inside of > 1024-byte region [ffff8801ca8adb00, ffff8801ca8adf00) > The buggy address belongs to the page: > page:ffffea00072a2b00 count:1 mapcount:0 mapping:ffff8801ca8ac000 index:0x0 > compound_mapcount: 0 > flags: 0x2fffc0000008100(slab|head) > raw: 02fffc0000008100 ffff8801ca8ac000 0000000000000000 0000000100000007 > raw: ffffea00072969a0 ffffea00072c5d20 ffff8801dac00ac0 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801ca8adb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801ca8adc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801ca8adc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8801ca8add00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801ca8add80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. Still reproducible on Linus' tree (commit 66e1c94db3cd4e) and on linux-next (next-20180511). Here's a simplified reproducer: #include <fcntl.h> #include <netinet/in.h> #include <pthread.h> #include <rdma/rdma_user_cm.h> #include <unistd.h> static int cmfd; static volatile uint64_t id; static void *thr1(void *_ignored) { for (;;) { struct { struct rdma_ucm_cmd_hdr hdr; struct rdma_ucm_create_id create; } msg = { .hdr = { .cmd = RDMA_USER_CM_CMD_CREATE_ID, .out = 8 }, .create = { .response = (unsigned long)&id, .ps = 2, /* RDMA_PS_IPOIB */ }, }; write(cmfd, &msg, sizeof(msg)); } } static void *thr2(void *_ignored) { for (;;) { struct { struct rdma_ucm_cmd_hdr hdr; struct rdma_ucm_bind_ip bind; } msg = { .hdr = { .cmd = RDMA_USER_CM_CMD_BIND_IP }, .bind = { .addr = { .sin6_family = AF_INET6, .sin6_addr = { .s6_addr = { 0xff } }, }, .id = id, }, }; write(cmfd, &msg, sizeof(msg)); } } static void *thr3(void *_ignored) { for (;;) { struct { struct rdma_ucm_cmd_hdr hdr; struct rdma_ucm_listen listen; } msg = { .hdr = { .cmd = RDMA_USER_CM_CMD_LISTEN }, .listen = { .id = id }, }; write(cmfd, &msg, sizeof(msg)); } } int main() { pthread_t t[3]; cmfd = open("/dev/infiniband/rdma_cm", O_WRONLY); pthread_create(&t[0], NULL, thr1, NULL); pthread_create(&t[1], NULL, thr2, NULL); pthread_create(&t[2], NULL, thr3, NULL); usleep(100000); } -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html