Messages in this thread | | | From | Dmitry Vyukov <> | Date | Thu, 26 Nov 2015 15:17:40 +0100 | Subject | GPF in process_one_work (flush_to_ldisc) |
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Hello,
The following program triggers GPF:
// autogenerated by syzkaller (http://github.com/google/syzkaller) #include <syscall.h> #include <string.h> #include <stdint.h>
int main() { long r0 = syscall(SYS_mmap, 0x20000000ul, 0x10000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); long r1 = syscall(SYS_pipe2, 0x20000000ul, 0x80000ul, 0, 0, 0, 0); long r2 = -1; if (r1 != -1) r2 = *(uint32_t*)0x20000000; long r3 = -1; if (r1 != -1) r3 = *(uint32_t*)0x20000004; long r6 = syscall(SYS_open, "/dev/ptmx", 0x1ul, 0x0ul, 0, 0, 0); long r10 = syscall(SYS_write, r6, 0x20001000ul, 0x1000ul, 0, 0, 0); *(uint32_t*)0x20003000 = 0x17; long r12 = syscall(SYS_ioctl, r6, 0x5423ul, 0x20003000ul, 0, 0, 0); long r18 = syscall(SYS_mmap, 0x20002000ul, 0x1000ul, 0x3ul, 0x32ul, r2, 0x0ul); long r20 = syscall(SYS_mmap, 0x20002000ul, 0x1000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); *(uint64_t*)0x20002000 = 0x2000225e; *(uint64_t*)0x20002008 = 0x56; *(uint64_t*)0x20002010 = 0x20002bc6; *(uint64_t*)0x20002018 = 0xe7; *(uint64_t*)0x20002020 = 0x20002fd7; *(uint64_t*)0x20002028 = 0x29; *(uint64_t*)0x20002030 = 0x20002f39; *(uint64_t*)0x20002038 = 0xc7; long r33 = syscall(SYS_writev, r3, 0x20002000ul, 0x4ul, 0, 0, 0); long r34 = syscall(SYS_dup2, r2, r6, 0, 0, 0, 0); return 0; }
BUG: unable to handle kernel NULL pointer dereference at (null) IP: [< (null)>] (null) PGD 3752d067 PUD 37a7b067 PMD 0 Oops: 0010 [#1] SMP KASAN Modules linked in: CPU: 2 PID: 148 Comm: kworker/u10:2 Not tainted 4.4.0-rc2+ #51 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: events_unbound flush_to_ldisc task: ffff88006da94440 ti: ffff88006db60000 task.ti: ffff88006db60000 RIP: 0010:[<0000000000000000>] [< (null)>] (null) RSP: 0018:ffff88006db67b50 EFLAGS: 00010246 RAX: 0000000000000102 RBX: ffff88003ab32f88 RCX: 0000000000000102 RDX: 0000000000000000 RSI: ffff88003ab330a6 RDI: ffff88003aabd388 RBP: ffff88006db67c48 R08: ffff88003ab32f9c R09: ffff88003ab31fb0 R10: ffff88003ab32fa8 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88006db67c20 R14: ffffffff863df820 R15: ffff88003ab31fb8 FS: 0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000037938000 CR4: 00000000000006e0 Stack: ffffffff829f46f1 ffff88006da94bf8 ffff88006da94bf8 0000000000000000 ffff88003ab31fb0 ffff88003aabd438 ffff88003ab31ff8 ffff88006430fd90 ffff88003ab32f9c ffffed0007557a87 1ffff1000db6cf78 ffff88003ab32078 Call Trace: [<ffffffff8127cf91>] process_one_work+0x8f1/0x17a0 kernel/workqueue.c:2030 [<ffffffff8127df14>] worker_thread+0xd4/0x1180 kernel/workqueue.c:2162 [<ffffffff8128faaf>] kthread+0x1cf/0x270 drivers/block/aoe/aoecmd.c:1302 [<ffffffff852a7c2f>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:468 Code: Bad RIP value. RIP [< (null)>] (null) RSP <ffff88006db67b50> CR2: 0000000000000000 ---[ end trace a587f8947e54d6ea ]---
strace output:
execve("./a.out", ["./a.out"], [/* 14 vars */]) = 0 brk(0) = 0x1590000 brk(0x15911c0) = 0x15911c0 arch_prctl(ARCH_SET_FS, 0x1590880) = 0 readlink("/proc/self/exe", "/root/a.out", 4096) = 11 brk(0x15b21c0) = 0x15b21c0 brk(0x15b3000) = 0x15b3000 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) mmap(0x20000000, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 pipe2([3, 4], O_CLOEXEC) = 0 open("/dev/ptmx", O_WRONLY) = 5 write(5, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 4096) = 4096 ioctl(5, TIOCSETD, [23]) = 0 mmap(0x20002000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, 3, 0) = 0x20002000 mmap(0x20002000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20002000 writev(4, [{"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 86}, {"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 231}, {"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 41}, {"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 199}], 4) = 557 dup2(3, 5
at this point VM hangs.
On commit 6ffeba9607343f15303a399bc402a538800d89d9 (Now 24).
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