+ "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: sysctl: sched: avoid using current->nsproxy\n\nUsing the 'net' structure via 'current' is not recommended for different\nreasons.\n\nFirst, if the goal is to use it to read or write per-netns data, this is\ninconsistent with how the \"generic\" sysctl entries are doing: directly\nby only using pointers set to the table entry, e.g. table->data. Linked\nto that, the per-netns data should always be obtained from the table\nlinked to the netns it had been created for, which may not coincide with\nthe reader's or writer's netns.\n\nAnother reason is that access to current->nsproxy->netns can oops if\nattempted when current->nsproxy had been dropped when the current task\nis exiting. This is what syzbot found, when using acct(2):\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN PTI\n KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]\n CPU: 1 UID: 0 PID: 5924 Comm: syz-executor Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\n RIP: 0010:proc_scheduler+0xc6/0x3c0 net/mptcp/ctrl.c:125\n Code: 03 42 80 3c 38 00 0f 85 fe 02 00 00 4d 8b a4 24 08 09 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 28 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 cc 02 00 00 4d 8b 7c 24 28 48 8d 84 24 c8 00 00\n RSP: 0018:ffffc900034774e8 EFLAGS: 00010206\n\n RAX: dffffc0000000000 RBX: 1ffff9200068ee9e RCX: ffffc90003477620\n RDX: 0000000000000005 RSI: ffffffff8b08f91e RDI: 0000000000000028\n RBP: 0000000000000001 R08: ffffc90003477710 R09: 0000000000000040\n R10: 0000000000000040 R11: 00000000726f7475 R12: 0000000000000000\n R13: ffffc90003477620 R14: ffffc90003477710 R15: dffffc0000000000\n FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007fee3cd452d8 CR3: 000000007d116000 CR4: 00000000003526f0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n <TASK>\n proc_sys_call_handler+0x403/0x5d0 fs/proc/proc_sysctl.c:601\n __kernel_write_iter+0x318/0xa80 fs/read_write.c:612\n __kernel_write+0xf6/0x140 fs/read_write.c:632\n do_acct_process+0xcb0/0x14a0 kernel/acct.c:539\n acct_pin_kill+0x2d/0x100 kernel/acct.c:192\n pin_kill+0x194/0x7c0 fs/fs_pin.c:44\n mnt_pin_kill+0x61/0x1e0 fs/fs_pin.c:81\n cleanup_mnt+0x3ac/0x450 fs/namespace.c:1366\n task_work_run+0x14e/0x250 kernel/task_work.c:239\n exit_task_work include/linux/task_work.h:43 [inline]\n do_exit+0xad8/0x2d70 kernel/exit.c:938\n do_group_exit+0xd3/0x2a0 kernel/exit.c:1087\n get_signal+0x2576/0x2610 kernel/signal.c:3017\n arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337\n exit_to_user_mode_loop kernel/entry/common.c:111 [inline]\n exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]\n __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]\n syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218\n do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n RIP: 0033:0x7fee3cb87a6a\n Code: Unable to access opcode bytes at 0x7fee3cb87a40.\n RSP: 002b:00007fffcccac688 EFLAGS: 00000202 ORIG_RAX: 0000000000000037\n RAX: 0000000000000000 RBX: 00007fffcccac710 RCX: 00007fee3cb87a6a\n RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003\n RBP: 0000000000000003 R08: 00007fffcccac6ac R09: 00007fffcccacac7\n R10: 00007fffcccac710 R11: 0000000000000202 R12: 00007fee3cd49500\n R13: 00007fffcccac6ac R14: 0000000000000000 R15: 00007fee3cd4b000\n </TASK>\n Modules linked in:\n ---[ end trace 0000000000000000 ]---\n RIP: 0010:proc_scheduler+0xc6/0x3c0 net/mptcp/ctrl.c:125\n Code: 03 42 80 3c 38 00 0f 85 fe 02 00 00 4d 8b a4 24 08 09 00 00 48 b8 00 00 00 00 00 fc\n---truncated---",
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