Hello Syzbot On Fri, 14 Jun 2019 02:26:02 +0800 syzbot wrote: > > Hello, > > syzbot has tested the proposed patch but the reproducer still triggered crash: > memory leak in vhost_net_ioctl > Oh sorry for my poor patch. > ANGE): hsr_slave_1: link becomes ready > 2019/06/13 18:24:57 executed programs: 18 > BUG: memory leak > unreferenced object 0xffff88811cbc6ac0 (size 64): > comm "syz-executor.0", pid 7196, jiffies 4294943804 (age 14.770s) > hex dump (first 32 bytes): > 01 00 00 00 81 88 ff ff 00 00 00 00 82 88 ff ff ................ > d0 6a bc 1c 81 88 ff ff d0 6a bc 1c 81 88 ff ff .j.......j...... > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > [<000000006c752978>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff88810b1365c0 (size 64): > comm "syz-executor.2", pid 7193, jiffies 4294943823 (age 14.580s) > hex dump (first 32 bytes): > 01 00 00 00 81 88 ff ff 00 00 00 00 81 88 ff ff ................ > d0 65 13 0b 81 88 ff ff d0 65 13 0b 81 88 ff ff .e.......e...... > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff88810be23700 (size 64): > comm "syz-executor.3", pid 7194, jiffies 4294943823 (age 14.580s) > hex dump (first 32 bytes): > 01 00 00 00 00 00 00 00 00 00 00 00 00 c9 ff ff ................ > 10 37 e2 0b 81 88 ff ff 10 37 e2 0b 81 88 ff ff .7.......7...... > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > [<000000006c752978>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff88810b136500 (size 64): > comm "syz-executor.6", pid 7228, jiffies 4294943827 (age 14.540s) > hex dump (first 32 bytes): > 01 00 00 00 20 69 6f 63 00 00 00 00 64 65 76 2f .... ioc....dev/ > 10 65 13 0b 81 88 ff ff 10 65 13 0b 81 88 ff ff .e.......e...... > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > [<000000006c752978>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff88810b9cfec0 (size 64): > comm "syz-executor.7", pid 7236, jiffies 4294943829 (age 14.520s) > hex dump (first 32 bytes): > 01 00 00 00 20 69 6f 63 00 00 00 00 64 65 76 2f .... ioc....dev/ > d0 fe 9c 0b 81 88 ff ff d0 fe 9c 0b 81 88 ff ff ................ > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive > include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > [<000000006c752978>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff88810b9cd380 (size 64): > comm "syz-executor.4", pid 7218, jiffies 4294943834 (age 14.470s) > hex dump (first 32 bytes): > 01 00 00 00 81 88 ff ff 00 00 00 00 81 88 ff ff ................ > 90 d3 9c 0b 81 88 ff ff 90 d3 9c 0b 81 88 ff ff ................ > backtrace: > [<000000006c752978>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] > [<000000006c752978>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<000000006c752978>] slab_alloc mm/slab.c:3326 [inline] > [<000000006c752978>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<00000000b3825d52>] kmalloc include/linux/slab.h:547 [inline] > [<00000000b3825d52>] vhost_net_ubuf_alloc drivers/vhost/net.c:241 [inline] > [<00000000b3825d52>] vhost_net_set_backend drivers/vhost/net.c:1535 [inline] > [<00000000b3825d52>] vhost_net_ioctl+0xb43/0xc10 drivers/vhost/net.c:1717 > [<00000000700f02d7>] vfs_ioctl fs/ioctl.c:46 [inline] > [<00000000700f02d7>] file_ioctl fs/ioctl.c:509 [inline] > [<00000000700f02d7>] do_vfs_ioctl+0x62a/0x810 fs/ioctl.c:696 > [<000000009a0ec0a7>] ksys_ioctl+0x86/0xb0 fs/ioctl.c:713 > [<00000000d9416323>] __do_sys_ioctl fs/ioctl.c:720 [inline] > [<00000000d9416323>] __se_sys_ioctl fs/ioctl.c:718 [inline] > [<00000000d9416323>] __x64_sys_ioctl+0x1e/0x30 fs/ioctl.c:718 > [<00000000e4407a23>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:301 > [<000000008715c149>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Tested on: > > commit: c11fb13a Merge branch 'for-linus' of git://git.kernel.org/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11c6b666a00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cb38d33cd06d8d48 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > patch: https://syzkaller.appspot.com/x/patch.diff?x=11ff0de1a00000 > And I want to try again the following tiny diff made based on the logic: 1_> vhost_net_ubuf_alloc() in the dump info suggests that it is ubuf leak. 2_> commit c38e39c378f4 ("vhost-net: fix use-after-free in vhost_net_flush") makes vhost_net_flush() no longer release ubuf. 3_> in both reset_owner and release pathes, see vhost_net_reset_owner() and vhost_net_release() please, vq is reset in wake of flush: vhost_net_flush(n); vhost_dev_stop(&n->dev); vhost_dev_cleanup(&n->dev); vhost_net_vq_reset(n); 4_> the ubufs pointer is cleared in vhost_net_vq_reset() #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master Can you give it a shoot please if there is not anything missed in the above logic? Thanks Hillf ------->8--- --- drivers/vhost/net.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 3beb401..87db9b3 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -309,6 +309,8 @@ static void vhost_net_vq_reset(struct vhost_net *n) for (i = 0; i < VHOST_NET_VQ_MAX; i++) { n->vqs[i].done_idx = 0; n->vqs[i].upend_idx = 0; + if (n->vqs[i].ubufs) + vhost_net_ubuf_put_wait_and_free(n->vqs[i].ubufs); n->vqs[i].ubufs = NULL; n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; -- _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
