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| author | Edward Adam Davis <eadavis@qq.com> | 2024-09-10 12:58:56 +0300 | 
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-09-12 02:00:11 +0300 | 
| commit | b4cd80b0338945a94972ac3ed54f8338d2da2076 (patch) | |
| tree | e4e1f60ac551f44f48cbb0333623f8c1356a8e6e /drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | |
| parent | 077ee7e6b13a2b6668196ed01a22023549e19381 (diff) | |
| download | linux-b4cd80b0338945a94972ac3ed54f8338d2da2076.tar.xz | |
mptcp: pm: Fix uaf in __timer_delete_sync
There are two paths to access mptcp_pm_del_add_timer, result in a race
condition:
     CPU1				CPU2
     ====                               ====
     net_rx_action
     napi_poll                          netlink_sendmsg
     __napi_poll                        netlink_unicast
     process_backlog                    netlink_unicast_kernel
     __netif_receive_skb                genl_rcv
     __netif_receive_skb_one_core       netlink_rcv_skb
     NF_HOOK                            genl_rcv_msg
     ip_local_deliver_finish            genl_family_rcv_msg
     ip_protocol_deliver_rcu            genl_family_rcv_msg_doit
     tcp_v4_rcv                         mptcp_pm_nl_flush_addrs_doit
     tcp_v4_do_rcv                      mptcp_nl_remove_addrs_list
     tcp_rcv_established                mptcp_pm_remove_addrs_and_subflows
     tcp_data_queue                     remove_anno_list_by_saddr
     mptcp_incoming_options             mptcp_pm_del_add_timer
     mptcp_pm_del_add_timer             kfree(entry)
In remove_anno_list_by_saddr(running on CPU2), after leaving the critical
zone protected by "pm.lock", the entry will be released, which leads to the
occurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).
Keeping a reference to add_timer inside the lock, and calling
sk_stop_timer_sync() with this reference, instead of "entry->add_timer".
Move list_del(&entry->list) to mptcp_pm_del_add_timer and inside the pm lock,
do not directly access any members of the entry outside the pm lock, which
can avoid similar "entry->x" uaf.
Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+f3a31fb909db9b2a5c4d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f3a31fb909db9b2a5c4d
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/tencent_7142963A37944B4A74EF76CD66EA3C253609@qq.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_object.c')
0 files changed, 0 insertions, 0 deletions
