On Thu, 04 Feb 2016 17:32:31 +0100, Dmitry Vyukov wrote: > > On Thu, Feb 4, 2016 at 5:24 PM, Takashi Iwai <tiwai@xxxxxxx> wrote: > > On Wed, 03 Feb 2016 17:24:56 +0100, > > Dmitry Vyukov wrote: > >> > >> Hello, > >> > >> The following program triggers use-after-free in snd_timer_start1: > >> > >> // autogenerated by syzkaller (http://github.com/google/syzkaller) > >> #include <pthread.h> > >> #include <stdint.h> > >> #include <string.h> > >> #include <sys/syscall.h> > >> #include <unistd.h> > >> > >> int main() > >> { > >> syscall(SYS_mmap, 0x20000000ul, 0x664000ul, 0x3ul, 0x32ul, > >> 0xfffffffffffffffful, 0x0ul); > >> int fd = syscall(SYS_open, "/dev/snd/timer", 0x40000ul, 0, 0, 0); > >> *(uint32_t*)0x20653000 = (uint32_t)0x1; > >> *(uint32_t*)0x20653004 = (uint32_t)0xfffffffffffffffe; > >> *(uint32_t*)0x20653008 = (uint32_t)0x8; > >> *(uint32_t*)0x2065300c = (uint32_t)0x0; > >> *(uint32_t*)0x20653010 = (uint32_t)0x0; > >> *(uint8_t*)0x20653014 = (uint8_t)0x0; > >> *(uint8_t*)0x20653015 = (uint8_t)0x0; > >> *(uint8_t*)0x20653016 = (uint8_t)0x0; > >> *(uint8_t*)0x20653017 = (uint8_t)0x0; > >> *(uint8_t*)0x20653018 = (uint8_t)0x0; > >> *(uint8_t*)0x20653019 = (uint8_t)0x0; > >> *(uint8_t*)0x2065301a = (uint8_t)0x0; > >> *(uint8_t*)0x2065301b = (uint8_t)0x0; > >> *(uint8_t*)0x2065301c = (uint8_t)0x0; > >> *(uint8_t*)0x2065301d = (uint8_t)0x0; > >> *(uint8_t*)0x2065301e = (uint8_t)0x0; > >> *(uint8_t*)0x2065301f = (uint8_t)0x0; > >> *(uint8_t*)0x20653020 = (uint8_t)0x0; > >> *(uint8_t*)0x20653021 = (uint8_t)0x0; > >> *(uint8_t*)0x20653022 = (uint8_t)0x0; > >> *(uint8_t*)0x20653023 = (uint8_t)0x0; > >> *(uint8_t*)0x20653024 = (uint8_t)0x0; > >> *(uint8_t*)0x20653025 = (uint8_t)0x0; > >> *(uint8_t*)0x20653026 = (uint8_t)0x0; > >> *(uint8_t*)0x20653027 = (uint8_t)0x0; > >> *(uint8_t*)0x20653028 = (uint8_t)0x0; > >> *(uint8_t*)0x20653029 = (uint8_t)0x0; > >> *(uint8_t*)0x2065302a = (uint8_t)0x0; > >> *(uint8_t*)0x2065302b = (uint8_t)0x0; > >> *(uint8_t*)0x2065302c = (uint8_t)0x0; > >> *(uint8_t*)0x2065302d = (uint8_t)0x0; > >> *(uint8_t*)0x2065302e = (uint8_t)0x0; > >> *(uint8_t*)0x2065302f = (uint8_t)0x0; > >> *(uint8_t*)0x20653030 = (uint8_t)0x0; > >> *(uint8_t*)0x20653031 = (uint8_t)0x0; > >> *(uint8_t*)0x20653032 = (uint8_t)0x0; > >> *(uint8_t*)0x20653033 = (uint8_t)0x0; > >> syscall(SYS_ioctl, fd, 0x40345410ul, 0x20653000ul, 0, 0, 0); > >> syscall(SYS_ioctl, fd, 0x54a0ul, 0, 0, 0, 0); > >> return 0; > >> } > >> > >> ================================================================== > >> BUG: KASAN: use-after-free in __list_add+0x233/0x22016/02/03 13:44:32 > >> executing program 0: > >> Read of size 8 by task syz-executor/27661 > >> > >> INFO: Allocated in snd_timer_instance_new+0x52/0x3a0 age=7 cpu=0 pid=27660 > >> [< inline >] slab_alloc_node mm/slub.c:2562 > >> [< inline >] slab_alloc mm/slub.c:2604 > >> [< none >] kmem_cache_alloc_trace+0x25c/0x300 mm/slub.c:2621 > >> [< inline >] kmalloc include/linux/slab.h:463 > >> [< inline >] kzalloc include/linux/slab.h:607 > >> [< none >] snd_timer_instance_new+0x52/0x3a0 sound/core/timer.c:106 > >> [< none >] snd_timer_open+0x522/0xd20 sound/core/timer.c:289 > >> [< inline >] snd_timer_user_tselect sound/core/timer.c:1598 > >> [< inline >] __snd_timer_user_ioctl sound/core/timer.c:1874 > >> [< none >] snd_timer_user_ioctl+0x8db/0x25f0 sound/core/timer.c:1904 > >> [< inline >] vfs_ioctl fs/ioctl.c:43 > >> [< none >] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674 > >> [< inline >] SYSC_ioctl fs/ioctl.c:689 > >> [< none >] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680 > >> [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a > >> arch/x86/entry/entry_64.S:185 > >> > >> INFO: Freed in snd_timer_close+0x3ee/0x750 age=9 cpu=3 pid=27661 > >> [< inline >] slab_free mm/slub.c:2835 > >> [< none >] kfree+0x2ac/0x2c0 mm/slub.c:3664 > >> [< none >] snd_timer_close+0x3ee/0x750 sound/core/timer.c:375 > >> [< inline >] snd_timer_user_tselect sound/core/timer.c:1588 > >> [< inline >] __snd_timer_user_ioctl sound/core/timer.c:1874 > >> [< none >] snd_timer_user_ioctl+0x7b6/0x25f0 sound/core/timer.c:1904 > >> [< inline >] vfs_ioctl fs/ioctl.c:43 > >> [< none >] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674 > >> [< inline >] SYSC_ioctl fs/ioctl.c:689 > >> [< none >] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680 > >> [< none >] entry_SYSCALL_64_fastpath+0x16/0x7a > >> arch/x86/entry/entry_64.S:185 > >> > >> Call Trace: > >> [< inline >] kasan_report mm/kasan/report.c:274 > >> [<ffffffff8176640e>] __asan_report_load8_noabort+0x3e/0x40 > >> mm/kasan/report.c:295 > >> [<ffffffff82c4a7e3>] __list_add+0x233/0x250 lib/list_debug.c:39 > >> [< inline >] list_move_tail include/linux/list.h:77 > >> [<ffffffff85240fdc>] snd_timer_start1+0x6c/0x2c0 sound/core/timer.c:432 > >> [<ffffffff85241a7b>] snd_timer_start+0x20b/0x2b0 sound/core/timer.c:499 > >> [< inline >] snd_timer_user_start sound/core/timer.c:1799 > >> [< inline >] __snd_timer_user_ioctl sound/core/timer.c:1883 > >> [<ffffffff85245fb7>] snd_timer_user_ioctl+0x767/0x25f0 sound/core/timer.c:1904 > >> [< inline >] vfs_ioctl fs/ioctl.c:43 > >> [<ffffffff817fa9ec>] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674 > >> [< inline >] SYSC_ioctl fs/ioctl.c:689 > >> [<ffffffff817fb89f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680 > >> [<ffffffff8665ebb6>] entry_SYSCALL_64_fastpath+0x16/0x7a > >> arch/x86/entry/entry_64.S:185 > >> ================================================================== > >> > >> > >> Sometimes it manifests as: > >> > >> ------------[ cut here ]------------ > >> WARNING: CPU: 1 PID: 6548 at lib/list_debug.c:42 __list_add+0x1db/0x250() > >> list_add corruption. prev->next should be next (ffff8800697c10e8), but > >> was ffff880030441fd0. (prev=ffff880030441fd0). > >> Modules linked in: > >> CPU: 1 PID: 6548 Comm: a.out Not tainted 4.5.0-rc2+ #309 > >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > >> 00000000ffffffff ffff88002fa17918 ffffffff82be2c8d ffff88002fa17988 > >> ffff88002fd62f80 ffffffff86acf380 ffff88002fa17958 ffffffff81355139 > >> ffffffff82c4a78b ffffed0005f42f2d ffffffff86acf380 000000000000002a > >> Call Trace: > >> [< inline >] __dump_stack lib/dump_stack.c:15 > >> [<ffffffff82be2c8d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 > >> [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 > >> [<ffffffff81355249>] warn_slowpath_fmt+0xa9/0xd0 kernel/panic.c:494 > >> [<ffffffff82c4a78b>] __list_add+0x1db/0x250 lib/list_debug.c:39 > >> [< inline >] list_move_tail include/linux/list.h:77 > >> [<ffffffff85240fdc>] snd_timer_start1+0x6c/0x2c0 sound/core/timer.c:432 > >> [<ffffffff85241a7b>] snd_timer_start+0x20b/0x2b0 sound/core/timer.c:499 > >> [< inline >] snd_timer_user_start sound/core/timer.c:1799 > >> [< inline >] __snd_timer_user_ioctl sound/core/timer.c:1883 > >> [<ffffffff85245fb7>] snd_timer_user_ioctl+0x767/0x25f0 sound/core/timer.c:1904 > >> [< inline >] vfs_ioctl fs/ioctl.c:43 > >> [<ffffffff817fa9ec>] do_vfs_ioctl+0x18c/0xfb0 fs/ioctl.c:674 > >> [< inline >] SYSC_ioctl fs/ioctl.c:689 > >> [<ffffffff817fb89f>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:680 > >> [<ffffffff8665ebb6>] entry_SYSCALL_64_fastpath+0x16/0x7a > >> arch/x86/entry/entry_64.S:185 > >> ---[ end trace 77da812dd399e78b ]--- > >> > >> On commit 34229b277480f46c1e9a19f027f30b074512e68b + recent fixes from Takashi. > > > > Thanks for the report. This is indeed an old bug, but it appears now > > more easily due to the recent fix to avoid double-stop. Below is the > > fix patch. topic/core-fixes branch was updated with this, too. > > > Fixes the crash for me. > I think this was the last one in sound that happened periodically > during fuzzing. Let's see what the fuzzer will say now :) > Thanks for quick fixes! Great, thanks for your patient reports and testing! Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
