On 03/23/2017 03:19 AM, Dmitry Vyukov wrote: > Hello, > > I've got the following BUG while running syzkaller fuzzer. > Note the injected kmalloc failure, most likely it's the root cause. Thanks Dmitry, The BUG indicates someone called region_chg() in the process of adding a hugetlbfs page reservation, but did not complete this 'two step' process with a call to region_add() or region_abort(). Most likely a missed call in an error path somewhere. :( I'll try to track this down. The hint of 'injected kmalloc failure' should help. -- Mike Kravetz > > > FAULT_INJECTION: forcing a failure. > name failslab, interval 1, probability 0, space 0, times 0 > CPU: 2 PID: 12823 Comm: syz-executor1 Not tainted 4.11.0-rc3+ #364 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:16 [inline] > dump_stack+0x1b8/0x28d lib/dump_stack.c:52 > fail_dump lib/fault-inject.c:45 [inline] > should_fail+0x78a/0x870 lib/fault-inject.c:154 > should_failslab+0xec/0x120 mm/failslab.c:31 > slab_pre_alloc_hook mm/slab.h:434 [inline] > slab_alloc mm/slab.c:3394 [inline] > kmem_cache_alloc_trace+0x206/0x720 mm/slab.c:3636 > kmalloc include/linux/slab.h:490 [inline] > region_chg+0x429/0xa80 mm/hugetlb.c:402 > hugetlb_reserve_pages+0x16d/0x540 mm/hugetlb.c:4334 > hugetlb_file_setup+0x40c/0x9f0 fs/hugetlbfs/inode.c:1289 > newseg+0x422/0xd30 ipc/shm.c:575 > ipcget_new ipc/util.c:285 [inline] > ipcget+0x21e/0x580 ipc/util.c:639 > SYSC_shmget ipc/shm.c:673 [inline] > SyS_shmget+0x158/0x230 ipc/shm.c:657 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > RIP: 0033:0x445b79 > RSP: 002b:00007f273aba1858 EFLAGS: 00000282 ORIG_RAX: 000000000000001d > RAX: ffffffffffffffda RBX: 0000000000708000 RCX: 0000000000445b79 > RDX: 0000000000000900 RSI: 0000000000003000 RDI: 0000000000000000 > RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000020000000 R11: 0000000000000282 R12: 00000000004a7e31 > R13: 0000000000000000 R14: 00007f273aba1618 R15: 00007f273aba1788 > ------------[ cut here ]------------ > kernel BUG at mm/hugetlb.c:742! > invalid opcode: 0000 [#1] SMP KASAN > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 2 PID: 12823 Comm: syz-executor1 Not tainted 4.11.0-rc3+ #364 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > task: ffff88006be3c0c0 task.stack: ffff88003daa0000 > RIP: 0010:resv_map_release+0x265/0x330 mm/hugetlb.c:742 > RSP: 0018:ffff88003daa7830 EFLAGS: 00010246 > RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffc90002253000 > RDX: 0000000000010000 RSI: ffffffff81976485 RDI: ffff88006b5bf950 > RBP: ffff88003daa78e0 R08: 1ffff1000d7c7a5b R09: 0000000000000000 > R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006b5bf958 > R13: ffffed0007b54f0f R14: ffff88006b5bf958 R15: ffff88006b5bf958 > FS: 00007f273aba2700(0000) GS:ffff88006e200000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f68fabe8000 CR3: 0000000014a09000 CR4: 00000000000026e0 > DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 > Call Trace: > hugetlbfs_evict_inode+0x7b/0xa0 fs/hugetlbfs/inode.c:493 > evict+0x481/0x920 fs/inode.c:553 > iput_final fs/inode.c:1515 [inline] > iput+0x62b/0xa20 fs/inode.c:1542 > hugetlb_file_setup+0x593/0x9f0 fs/hugetlbfs/inode.c:1306 > newseg+0x422/0xd30 ipc/shm.c:575 > ipcget_new ipc/util.c:285 [inline] > ipcget+0x21e/0x580 ipc/util.c:639 > SYSC_shmget ipc/shm.c:673 [inline] > SyS_shmget+0x158/0x230 ipc/shm.c:657 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > RIP: 0033:0x445b79 > RSP: 002b:00007f273aba1858 EFLAGS: 00000282 ORIG_RAX: 000000000000001d > RAX: ffffffffffffffda RBX: 0000000000708000 RCX: 0000000000445b79 > RDX: 0000000000000900 RSI: 0000000000003000 RDI: 0000000000000000 > RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000020000000 R11: 0000000000000282 R12: 00000000004a7e31 > R13: 0000000000000000 R14: 00007f273aba1618 R15: 00007f273aba1788 > Code: 00 fc ff df 48 c7 04 01 00 00 00 00 c7 44 08 08 00 00 00 00 48 > 81 c4 88 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 ab a5 d5 ff <0f> > 0b 48 8b bd 70 ff ff ff e8 ad c0 03 00 e9 2c fe ff ff e8 a3 > RIP: resv_map_release+0x265/0x330 mm/hugetlb.c:742 RSP: ffff88003daa7830 > ---[ end trace 575ce95655b30bd0 ]--- > > On commit 093b995e3b55a0ae0670226ddfcb05bfbf0099ae > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
