RE: [syzbot] [rdma?] KASAN: slab-use-after-free Read in siw_query_port (2)

Bernard Metzler
2024-11-27T12:57:51Z

> -----Original Message-----
> From: syzbot <syzbot+67a887427af54ecb7c93@syzkaller.appspotmail.com>
> Sent: Wednesday, November 27, 2024 10:49 AM
> To: Bernard Metzler <BMT@zurich.ibm.com>; jgg@ziepe.ca; leon@kernel.org;
> linux-kernel@vger.kernel.org; linux-rdma@vger.kernel.org;
> netdev@vger.kernel.org; syzkaller-bugs@googlegroups.com
> Subject: [EXTERNAL] [syzbot] [rdma?] KASAN: slab-use-after-free Read in
> siw_query_port (2)
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 5d066766c5f1 net/l2tp: fix warning in l2tp_exit_net found
> ..
> git tree: net
> console output: https%
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> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for
> Debian) 2.40
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>
> xfrm0 speed is unknown, defaulting to 1000
> ==================================================================
> BUG: KASAN: slab-use-after-free in siw_query_port+0x348/0x440
> drivers/infiniband/sw/siw/siw_verbs.c:183
> Read of size 4 at addr ffff88802ff88038 by task kworker/0:5/5883
>
> CPU: 0 UID: 0 PID: 5883 Comm: kworker/0:5 Not tainted 6.12.0-syzkaller-
> 05491-g5d066766c5f1 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 09/13/2024
> Workqueue: infiniband ib_cache_event_task
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:94 [inline]
> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
> print_address_description mm/kasan/report.c:377 [inline]
> print_report+0x169/0x550 mm/kasan/report.c:488
> kasan_report+0x143/0x180 mm/kasan/report.c:601
> siw_query_port+0x348/0x440 drivers/infiniband/sw/siw/siw_verbs.c:183
> ib_cache_update+0x1a9/0xb80 drivers/infiniband/core/cache.c:1494
> ib_cache_event_task+0xf3/0x1e0 drivers/infiniband/core/cache.c:1568
> process_one_work kernel/workqueue.c:3229 [inline]
> process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
> worker_thread+0x870/0xd30 kernel/workqueue.c:3391
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
> </TASK>
>

Here siw is getting a use-after-free when accessing the netdev in
query_port() verb, since the netdev got free'd already. I was
assuming the rdma core would serialize device deallocation
and driver access accordingly. Seems not to be the case?

Looking at somewhat similar rxe driver, I see a mutex protecting
netdev access in rxe_query_port() - 'rxe->usdev_lock'. That
mutex is used only right there and I don't see how it is useful.
@Zhu, was it intended to serialize netdev access?

Many thanks,
Bernard.

> Allocated by task 10564:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
> kasan_kmalloc include/linux/kasan.h:257 [inline]
> __do_kmalloc_node mm/slub.c:4264 [inline]
> __kmalloc_node_noprof+0x22a/0x440 mm/slub.c:4270
> __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658
> alloc_netdev_mqs+0xa4/0x1080 net/core/dev.c:11203
> rtnl_create_link+0x2f9/0xc20 net/core/rtnetlink.c:3595
> rtnl_newlink_create+0x210/0xa30 net/core/rtnetlink.c:3770
> __rtnl_newlink net/core/rtnetlink.c:3897 [inline]
> rtnl_newlink+0x17dd/0x24f0 net/core/rtnetlink.c:4007
> rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6917
> netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542
> netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
> netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
> netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
> sock_sendmsg_nosec net/socket.c:711 [inline]
> __sock_sendmsg+0x221/0x270 net/socket.c:726
> __sys_sendto+0x363/0x4c0 net/socket.c:2197
> __do_sys_sendto net/socket.c:2204 [inline]
> __se_sys_sendto net/socket.c:2200 [inline]
> __x64_sys_sendto+0xde/0x100 net/socket.c:2200
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Freed by task 35:
> kasan_save_stack mm/kasan/common.c:47 [inline]
> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
> kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
> poison_slab_object mm/kasan/common.c:247 [inline]
> __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
> kasan_slab_free include/linux/kasan.h:230 [inline]
> slab_free_hook mm/slub.c:2342 [inline]
> slab_free mm/slub.c:4579 [inline]
> kfree+0x1a0/0x440 mm/slub.c:4727
> device_release+0x99/0x1c0
> kobject_cleanup lib/kobject.c:689 [inline]
> kobject_release lib/kobject.c:720 [inline]
> kref_put include/linux/kref.h:65 [inline]
> kobject_put+0x22f/0x480 lib/kobject.c:737
> netdev_run_todo+0xe79/0x1000 net/core/dev.c:10918
> cleanup_net+0x762/0xcc0 net/core/net_namespace.c:628
> process_one_work kernel/workqueue.c:3229 [inline]
> process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
> worker_thread+0x870/0xd30 kernel/workqueue.c:3391
> kthread+0x2f0/0x390 kernel/kthread.c:389
> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> The buggy address belongs to the object at ffff88802ff88000
> which belongs to the cache kmalloc-cg-4k of size 4096
> The buggy address is located 56 bytes inside of
> freed 4096-byte region [ffff88802ff88000, ffff88802ff89000)
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ff88
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> memcg:ffff888031975541
> flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 00fff00000000040 ffff88801b04f500 ffffea0001f8f800 dead000000000002
> raw: 0000000000000000 0000000000040004 00000001f5000000 ffff888031975541
> head: 00fff00000000040 ffff88801b04f500 ffffea0001f8f800 dead000000000002
> head: 0000000000000000 0000000000040004 00000001f5000000 ffff888031975541
> head: 00fff00000000003 ffffea0000bfe201 ffffffffffffffff 0000000000000000
> head: 0000000000000008 0000000000000000 00000000ffffffff 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_NOMEM
> ALLOC), pid 7294, tgid 7294 (udevd), ts 104300491113, free_ts 104288279948
> set_page_owner include/linux/page_owner.h:32 [inline]
> post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
> prep_new_page mm/page_alloc.c:1564 [inline]
> get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474
> __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
> alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
> alloc_slab_page+0x6a/0x140 mm/slub.c:2412
> allocate_slab+0x5a/0x2f0 mm/slub.c:2578
> new_slab mm/slub.c:2631 [inline]
> ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
> __slab_alloc+0x58/0xa0 mm/slub.c:3908
> __slab_alloc_node mm/slub.c:3961 [inline]
> slab_alloc_node mm/slub.c:4122 [inline]
> __do_kmalloc_node mm/slub.c:4263 [inline]
> __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4270
> __kvmalloc_node_noprof+0x72/0x190 mm/util.c:658
> seq_buf_alloc fs/seq_file.c:38 [inline]
> seq_read_iter+0x20c/0xd70 fs/seq_file.c:210
> new_sync_read fs/read_write.c:484 [inline]
> vfs_read+0x991/0xb70 fs/read_write.c:565
> ksys_read+0x18f/0x2b0 fs/read_write.c:708
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> page last free pid 7342 tgid 7342 stack trace:
> reset_page_owner include/linux/page_owner.h:25 [inline]
> free_pages_prepare mm/page_alloc.c:1127 [inline]
> free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657
> discard_slab mm/slub.c:2677 [inline]
> __put_partials+0xeb/0x130 mm/slub.c:3145
> put_cpu_partial+0x17c/0x250 mm/slub.c:3220
> __slab_free+0x2ea/0x3d0 mm/slub.c:4449
> qlink_free mm/kasan/quarantine.c:163 [inline]
> qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
> kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
> __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
> kasan_slab_alloc include/linux/kasan.h:247 [inline]
> slab_post_alloc_hook mm/slub.c:4085 [inline]
> slab_alloc_node mm/slub.c:4134 [inline]
> kmem_cache_alloc_lru_noprof+0x139/0x2b0 mm/slub.c:4153
> sock_alloc_inode+0x28/0xc0 net/socket.c:307
> alloc_inode+0x65/0x1a0 fs/inode.c:336
> sock_alloc net/socket.c:615 [inline]
> __sock_create+0x127/0xa30 net/socket.c:1522
> sock_create net/socket.c:1616 [inline]
> __sys_socket_create net/socket.c:1653 [inline]
> __sys_socket+0x150/0x3c0 net/socket.c:1700
> __do_sys_socket net/socket.c:1714 [inline]
> __se_sys_socket net/socket.c:1712 [inline]
> __x64_sys_socket+0x7a/0x90 net/socket.c:1712
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Memory state around the buggy address:
> ffff88802ff87f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff88802ff87f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> >ffff88802ff88000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88802ff88080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88802ff88100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
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