| Message ID | 20200723075749.13043-1-qiang.zhang@windriver.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ceph: KASAN: use-after-free Read in ceph_mdsc_destroy | expand |
On Thu, 2020-07-23 at 15:57 +0800, qiang.zhang@windriver.com wrote: > From: Zhang Qiang <qiang.zhang@windriver.com> > > When the mdsc ptr is free, we should assign "thefsc->mdsc" a null ptr, > in ceph_mdsc_init func. > > CPU: 0 PID: 15653 Comm: syz-executor.3 Not tainted 5.8.0-rc5-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x18f/0x20d lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0xae/0x436 > mm/kasan/report.c:383 > __kasan_report mm/kasan/report.c:513 [inline] > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 > timer_is_static_object+0x7a/0x90 kernel/time/timer.c:611 > debug_object_assert_init lib/debugobjects.c:866 [inline] > debug_object_assert_init+0x1df/0x2e0 lib/debugobjects.c:841 > debug_timer_assert_init kernel/time/timer.c:728 [inline] > debug_assert_init kernel/time/timer.c:773 [inline] > del_timer+0x6d/0x110 kernel/time/timer.c:1196 > try_to_grab_pending kernel/workqueue.c:1249 [inline] > __cancel_work_timer+0x12d/0x700 kernel/workqueue.c:3092 > ceph_mdsc_stop fs/ceph/mds_client.c:4660 [inline] > ceph_mdsc_destroy+0x50/0x140 fs/ceph/mds_client.c:4679 > destroy_fs_client+0x13/0x200 fs/ceph/super.c:720 > ceph_get_tree+0x9e5/0x1660 fs/ceph/super.c:1110 > vfs_get_tree+0x89/0x2f0 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > do_mount+0x1592/0x1fe0 fs/namespace.c:3200 > __do_sys_mount fs/namespace.c:3410 [inline] > __se_sys_mount fs/namespace.c:3387 [inline] > __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x45c1d9 > Code: Bad RIP value. > RSP: 002b:00007f33d2bc0c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 > RAX: ffffffffffffffda RBX: 000000000001f400 RCX: 000000000045c1d9 > RDX: 0000000020000140 RSI: 00000000200000c0 RDI: 00000000200005c0 > RBP: 000000000078bf50 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c > R13: 00007fffaad3cc8f R14: 00007f33d2bc19c0 R15: 000000000078bf0c > > Allocated by task 15653: > save_stack+0x1b/0x40 mm/kasan/common.c:48 > set_track mm/kasan/common.c:56 [inline] > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 > kmem_cache_alloc_trace+0x14f/0x2d0 mm/slab.c:3551 > kmalloc include/linux/slab.h:555 [inline] > kzalloc include/linux/slab.h:669 [inline] > ceph_mdsc_init+0x47/0xf10 fs/ceph/mds_client.c:4351 > ceph_get_tree+0x4fe/0x1660 fs/ceph/super.c:1063 > vfs_get_tree+0x89/0x2f0 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > do_mount+0x1592/0x1fe0 fs/namespace.c:3200 > __do_sys_mount fs/namespace.c:3410 [inline] > __se_sys_mount fs/namespace.c:3387 [inline] > __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Freed by task 15653: > save_stack+0x1b/0x40 mm/kasan/common.c:48 > set_track mm/kasan/common.c:56 [inline] > kasan_set_free_info mm/kasan/common.c:316 [inline] > __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 > __cache_free mm/slab.c:3426 [inline] > kfree+0x103/0x2c0 mm/slab.c:3757 > ceph_mdsc_init+0xc64/0xf10 fs/ceph/mds_client.c:4422 > ceph_get_tree+0x4fe/0x1660 fs/ceph/super.c:1063 > vfs_get_tree+0x89/0x2f0 fs/super.c:1547 > do_new_mount fs/namespace.c:2875 [inline] > do_mount+0x1592/0x1fe0 fs/namespace.c:3200 > __do_sys_mount fs/namespace.c:3410 [inline] > __se_sys_mount fs/namespace.c:3387 [inline] > __x64_sys_mount+0x18f/0x230 fs/namespace.c:3387 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > The buggy address belongs to the object at ffff88809e482000 > which belongs to the cache kmalloc-4k of size 4096 > The buggy address is located 896 bytes inside of > 4096-byte region [ffff88809e482000, ffff88809e483000) > The buggy address belongs to the page: > page:ffffea0002792080 refcount:1 mapcount:0 mapping:0000000000000000 > index:0x0 head:ffffea0002792080 order:1 compound_mapcount:0 > flags: 0xfffe0000010200(slab|head) > raw: 00fffe0000010200 ffffea0002792008 ffffea000241dc08 ffff8880aa002000 > raw: 0000000000000000 ffff88809e482000 0000000100000001 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff88809e482280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff88809e482300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff88809e482380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff88809e482400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff88809e482480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > Fixes: f9009efac49c ("ceph: add dentry lease metric support") > > Reported-by: syzbot+b57f46d8d6ea51960b8c@syzkaller.appspotmail.com > Signed-off-by: Zhang Qiang <qiang.zhang@windriver.com> > --- > fs/ceph/mds_client.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index a50497142e59..6d819c285b05 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -4420,6 +4420,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) > kfree(mdsc->mdsmap); > err_mdsc: > kfree(mdsc); > + fsc->mdsc = NULL; > return err; > } > Hi Qiang, Thanks for the contribution. Xiubo just sent a patch for the same problem, so I'm dropping this one. Thanks!
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index a50497142e59..6d819c285b05 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -4420,6 +4420,7 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) kfree(mdsc->mdsmap); err_mdsc: kfree(mdsc); + fsc->mdsc = NULL; return err; }