Re: [PATCH 1/1] gtp: fix use-after-free and null-ptr-deref in gtp_genl_dump_pdp()

From: kovalev
Date: Wed Jan 24 2024 - 06:20:31 EST


24.01.2024 13:57, Eric Dumazet wrote:
Oh wait, this is a 5.10 kernel ?
Yes, but the bug is reproduced on the latest stable kernels.
Please generate a stack trace using a recent tree, it is possible the
bug has been fixed already.

See [PATCH 0/1] above, there's a stack for the 6.6.13 kernel at the bottom of the message.

[ 523.915255] Call Trace:
[ 523.915255] <TASK>
[ 523.915255] ? __die+0x1f/0x70
[ 523.915255] ? page_fault_oops+0x14d/0x4a0
[ 523.915255] ? exc_page_fault+0x7b/0x180
[ 523.915255] ? asm_exc_page_fault+0x22/0x30
[ 523.915255] ? gtp_genl_dump_pdp+0x82/0x190 [gtp]
[ 523.915255] ? gtp_genl_dump_pdp+0x82/0x190 [gtp]
[ 523.915255] genl_dumpit+0x2f/0x90
[ 523.915255] netlink_dump+0x126/0x320
[ 523.915255] __netlink_dump_start+0x1da/0x2a0
[ 523.915255] genl_family_rcv_msg_dumpit+0x93/0x100
[ 523.915255] ? __pfx_genl_start+0x10/0x10
[ 523.915255] ? __pfx_genl_dumpit+0x10/0x10
[ 523.915255] ? __pfx_genl_done+0x10/0x10
[ 523.915255] genl_rcv_msg+0x112/0x2a0
[ 523.915255] ? __pfx_gtp_genl_dump_pdp+0x10/0x10 [gtp]
[ 523.915255] ? __pfx_genl_rcv_msg+0x10/0x10
[ 523.915255] netlink_rcv_skb+0x54/0x110
[ 523.915255] genl_rcv+0x24/0x40
[ 523.915255] netlink_unicast+0x19f/0x290
[ 523.915255] netlink_sendmsg+0x250/0x4e0
[ 523.915255] ____sys_sendmsg+0x376/0x3b0
[ 523.915255] ? copy_msghdr_from_user+0x6d/0xb0
[ 523.915255] ___sys_sendmsg+0x86/0xe0
[ 523.915255] ? do_fault+0x296/0x470
[ 523.915255] ? __handle_mm_fault+0x771/0xda0
[ 523.915255] __sys_sendmsg+0x57/0xb0
[ 523.915255] do_syscall_64+0x59/0x90
[ 523.915255] ? ct_kernel_exit.isra.0+0x71/0x90
[ 523.915255] ? __ct_user_enter+0x5a/0xd0
[ 523.915255] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 523.915255] RIP: 0033:0x7f2bcb93cd49

--
Regards,
Vasiliy Kovalev