Re: KASAN: use-after-free Read in rdma_resolve_addr
From: Dmitry Vyukov
Date: Wed Feb 20 2019 - 10:22:13 EST
On Wed, Sep 26, 2018 at 4:27 PM syzbot
<syzbot+5013f86be1187ccf3800@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 846e8dd47c26 Merge tag 'scsi-fixes' of git://git.kernel.or..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=113cfbfa400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=dfb440e26f0a6f6f
> dashboard link: https://syzkaller.appspot.com/bug?extid=5013f86be1187ccf3800
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+5013f86be1187ccf3800@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> binder: 12750:12764 transaction failed 29201/-71, size 0-8 line 2762
> audit: type=1326 audit(1537939130.796:20382): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=228 compat=0
> ip=0x45a3da code=0x50000
> ==================================================================
> BUG: KASAN: use-after-free in rdma_resolve_addr+0x1e97/0x2730
> drivers/infiniband/core/cma.c:2981
> Read of size 2 at addr ffff88018529b1e0 by task syz-executor2/12772
This seems to have been fixed by:
#syz fix: ucma: fix a use-after-free in ucma_resolve_ip()
So let's close the bug. Pile of neglected bug reports is not too useful.
> CPU: 1 PID: 12772 Comm: syz-executor2 Not tainted 4.19.0-rc5+ #254
> audit: type=1326 audit(1537939130.846:20383): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> 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+0x1c4/0x2b4 lib/dump_stack.c:113
> print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
> kasan_report_error mm/kasan/report.c:354 [inline]
> kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
> __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:431
> rdma_resolve_addr+0x1e97/0x2730 drivers/infiniband/core/cma.c:2981
> audit: type=1326 audit(1537939130.846:20384): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=228 compat=0
> ip=0x45a3da code=0x50000
> ucma_resolve_ip+0x242/0x2a0 drivers/infiniband/core/ucma.c:713
> ucma_write+0x336/0x420 drivers/infiniband/core/ucma.c:1686
> audit: type=1326 audit(1537939130.866:20385): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=298 compat=0
> ip=0x457579 code=0x50000
> __vfs_write+0x119/0x9f0 fs/read_write.c:485
> audit: type=1326 audit(1537939130.866:20386): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=228 compat=0
> ip=0x45a3da code=0x50000
> vfs_write+0x1fc/0x560 fs/read_write.c:549
> ksys_write+0x101/0x260 fs/read_write.c:598
> __do_sys_write fs/read_write.c:610 [inline]
> __se_sys_write fs/read_write.c:607 [inline]
> __x64_sys_write+0x73/0xb0 fs/read_write.c:607
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> audit: type=1326 audit(1537939130.876:20387): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x457579
> Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> audit: type=1326 audit(1537939130.876:20388): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> RSP: 002b:00007f451b87cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
> RDX: 0000000000000048 RSI: 0000000020000240 RDI: 0000000000000009
> RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f451b87d6d4
> R13: 00000000004cb6a0 R14: 00000000004d8cb8 R15: 00000000ffffffff
>
> binder: BINDER_SET_CONTEXT_MGR already set
> Allocated by task 12777:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
> kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620
> kmalloc include/linux/slab.h:513 [inline]
> kzalloc include/linux/slab.h:707 [inline]
> __rdma_create_id+0xdf/0x790 drivers/infiniband/core/cma.c:784
> ucma_create_id+0x39b/0x990 drivers/infiniband/core/ucma.c:504
> binder: 12750:12773 ioctl 40046207 0 returned -16
> ucma_write+0x336/0x420 drivers/infiniband/core/ucma.c:1686
> __vfs_write+0x119/0x9f0 fs/read_write.c:485
> vfs_write+0x1fc/0x560 fs/read_write.c:549
> ksys_write+0x101/0x260 fs/read_write.c:598
> __do_sys_write fs/read_write.c:610 [inline]
> __se_sys_write fs/read_write.c:607 [inline]
> __x64_sys_write+0x73/0xb0 fs/read_write.c:607
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> audit: type=1326 audit(1537939130.886:20389): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> Freed by task 12770:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
> kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
> __cache_free mm/slab.c:3498 [inline]
> kfree+0xcf/0x230 mm/slab.c:3813
> rdma_destroy_id+0x835/0xcc0 drivers/infiniband/core/cma.c:1739
> ucma_close+0x100/0x300 drivers/infiniband/core/ucma.c:1765
> __fput+0x385/0xa30 fs/file_table.c:278
> ____fput+0x15/0x20 fs/file_table.c:309
> task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
> tracehook_notify_resume include/linux/tracehook.h:193 [inline]
> exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
> audit: type=1326 audit(1537939130.926:20390): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
> syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
> do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> audit: type=1326 audit(1537939130.926:20391): auid=4294967295 uid=0 gid=0
> ses=4294967295 subj==unconfined pid=12758 comm="syz-executor4"
> exe="/root/syz-executor4" sig=0 arch=c000003e syscall=202 compat=0
> ip=0x457579 code=0x50000
> The buggy address belongs to the object at ffff88018529b1c0
> which belongs to the cache kmalloc-2048 of size 2048
> The buggy address is located 32 bytes inside of
> 2048-byte region [ffff88018529b1c0, ffff88018529b9c0)
> The buggy address belongs to the page:
> page:ffffea000614a680 count:1 mapcount:0 mapping:ffff8801da800c40
> index:0xffff88018529a940
> binder: 12750:12764 ERROR: BC_REGISTER_LOOPER called without request
> compound_mapcount: 0
> flags: 0x2fffc0000008100(slab|head)
> raw: 02fffc0000008100 ffffea00061c4188 ffffea000632af08 ffff8801da800c40
> raw: ffff88018529a940 ffff88018529a0c0 0000000100000002 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff88018529b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88018529b100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
> > ffff88018529b180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
> ^
> ffff88018529b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88018529b280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
> kobject: 'loop5' (000000002cf6e86e): kobject_uevent_env
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx
>
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>
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