Hao Sun <sunhao.th@xxxxxxxxx> 于2021年9月17日周五 上午9:01写道： > > Jason Gunthorpe <jgg@xxxxxxxx> 于2021年9月17日周五 上午2:35写道： > > > > On Tue, Apr 13, 2021 at 10:19:25PM +0800, Hao Sun wrote: > > > Jason Gunthorpe <jgg@xxxxxxxx> 于2021年4月13日周二 下午9:45写道： > > > > > > > > On Tue, Apr 13, 2021 at 09:42:43PM +0800, Hao Sun wrote: > > > > > Jason Gunthorpe <jgg@xxxxxxxx> 于2021年4月13日周二 下午9:34写道： > > > > > > > > > > > > On Tue, Apr 13, 2021 at 11:36:41AM +0800, Hao Sun wrote: > > > > > > > Hi > > > > > > > > > > > > > > When using Healer(https://github.com/SunHao-0/healer/tree/dev) to fuzz > > > > > > > the Linux kernel, I found two use-after-free bugs which have been > > > > > > > reported a long time ago by Syzbot. > > > > > > > Although the corresponding patches have been merged into upstream, > > > > > > > these two bugs can still be triggered easily. > > > > > > > The original information about Syzbot report can be found here: > > > > > > > https://syzkaller.appspot.com/bug?id=8dc0bcd9dd6ec915ba10b3354740eb420884acaa > > > > > > > https://syzkaller.appspot.com/bug?id=95f89b8fb9fdc42e28ad586e657fea074e4e719b > > > > > > > > > > > > Then why hasn't syzbot seen this in a year's time? Seems strange > > > > > > > > > > > > > > > > Seems strange to me too, but the fact is that the reproduction program > > > > > in attachment can trigger these two bugs quickly. > > > > > > > > Do you have this in the C format? > > > > > > > > > > Just tried to use syz-prog2c to convert the repro-prog to C format. > > > The repro program of rdma_listen was successfully reproduced > > > (uploaded in attachment), the other one failed. it looks like > > > syz-prog2c may not be able to do the equivalent conversion. > > > You can use syz-execprog to execute the reprogram directly, this > > > method can reproduce both crashes, I have tried it. > > > > Can you check this patch that should solve it? > > > > https://patchwork.kernel.org/project/linux-rdma/patch/0-v1-9fbb33f5e201+2a-cma_listen_jgg@xxxxxxxxxx/ > > > > Just executed the original Syz prog on the latest Linux kernel > (ff1ffd71d5f0 Merge tag 'hyperv-fixes-signed-20210915'), it did not > crash the kernel. I've checked that the above patch has not been > merged into the latest commit. Therefore, there might be some other > commits that fixed that issue. > Sorry, I made a mistake. The C reproducer can still crash the latest version of the Linux kernel **without** patching the code from here (https://patchwork.kernel.org/project/linux-rdma/patch/0-v1-9fbb33f5e201+2a-cma_listen_jgg@xxxxxxxxxx/). ================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26 Read of size 8 at addr ffff8880189211e0 by task a.out/6637 CPU: 0 PID: 6637 Comm: a.out Not tainted 5.15.0-rc1+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x93/0x334 mm/kasan/report.c:256 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 __list_add_valid+0x93/0xa0 lib/list_debug.c:26 __list_add include/linux/list.h:67 [inline] list_add_tail include/linux/list.h:100 [inline] cma_listen_on_all drivers/infiniband/core/cma.c:2563 [inline] rdma_listen+0x7d2/0xeb0 drivers/infiniband/core/cma.c:3813 ucma_listen+0x16a/0x210 drivers/infiniband/core/ucma.c:1102 ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732 vfs_write+0x22a/0xae0 fs/read_write.c:592 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f3352746469 Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ff 49 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc7cfa3f68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000200003a8 RCX: 00007f3352746469 RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007ffc7cfa4070 R08: 4e22224e4e24244e R09: 4e22224e4e24244e R10: 0000000000000000 R11: 0000000000000246 R12: 0000561d50400fb0 R13: 00007ffc7cfa41b0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6636: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x186/0x340 mm/slub.c:3233 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] __rdma_create_id+0x5b/0x550 drivers/infiniband/core/cma.c:839 rdma_create_user_id+0x79/0xd0 drivers/infiniband/core/cma.c:893 ucma_create_id+0x162/0x360 drivers/infiniband/core/ucma.c:461 ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732 vfs_write+0x22a/0xae0 fs/read_write.c:592 ksys_write+0x1ee/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 6636: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0x100/0x140 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook mm/slub.c:1725 [inline] slab_free mm/slub.c:3483 [inline] kfree+0xfc/0x700 mm/slub.c:4543 ucma_close_id+0x4c/0x90 drivers/infiniband/core/ucma.c:185 ucma_destroy_private_ctx+0x887/0xb00 drivers/infiniband/core/ucma.c:576 ucma_close+0x10a/0x180 drivers/infiniband/core/ucma.c:1797 __fput+0x288/0x9f0 fs/file_table.c:280 task_work_run+0xe0/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xbbe/0x2dd0 kernel/exit.c:825 do_group_exit+0x125/0x340 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888018921000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 480 bytes inside of 2048-byte region [ffff888018921000, ffff888018921800) The buggy address belongs to the page: page:ffffea0000624800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x18920 head:ffffea0000624800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 0000000300000001 ffff888010c42000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 12722123527, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2418 [inline] prep_new_page+0x1a5/0x240 mm/page_alloc.c:2424 get_page_from_freelist+0x1f10/0x3b70 mm/page_alloc.c:4153 __alloc_pages+0x306/0x6e0 mm/page_alloc.c:5375 alloc_page_interleave+0x1e/0x1f0 mm/mempolicy.c:2042 alloc_pages+0x1e4/0x240 mm/mempolicy.c:2192 alloc_slab_page mm/slub.c:1763 [inline] allocate_slab mm/slub.c:1900 [inline] new_slab+0x34a/0x480 mm/slub.c:1963 ___slab_alloc+0xa9f/0x10d0 mm/slub.c:2994 __slab_alloc.isra.0+0x4d/0xa0 mm/slub.c:3081 slab_alloc_node mm/slub.c:3172 [inline] slab_alloc mm/slub.c:3214 [inline] __kmalloc+0x32e/0x390 mm/slub.c:4387 kmalloc include/linux/slab.h:596 [inline] kzalloc include/linux/slab.h:721 [inline] __register_sysctl_table+0xc3/0x1000 fs/proc/proc_sysctl.c:1318 __devinet_sysctl_register+0x156/0x280 net/ipv4/devinet.c:2577 devinet_sysctl_register net/ipv4/devinet.c:2617 [inline] devinet_sysctl_register+0x160/0x230 net/ipv4/devinet.c:2607 inetdev_init+0x269/0x570 net/ipv4/devinet.c:276 inetdev_event+0xdde/0x12f0 net/ipv4/devinet.c:1530 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info net/core/dev.c:1996 [inline] call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1981 page_owner free stack trace missing Memory state around the buggy address: ffff888018921080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888018921100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888018921180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888018921200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888018921280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== However, after patching the code, the crash can not be reproduced. Therefore, that patch did fix the problem. Regards Hao
