In the Linux kernel, the following vulnerability has been resolved:
ipv6: avoid possible NULL deref in rt6_uncached_list_flush_dev()
Blamed commit accidentally removed a check for rt->rt6i_idev being NULL, as spotted by syzbot:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 10998 Comm: syz-executor Not tainted 6.11.0-rc6-syzkaller-00208-g625403177711 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:rt6_uncached_list_flush_dev net/ipv6/route.c:177 [inline] RIP: 0010:rt6_disable_ip+0x33e/0x7e0 net/ipv6/route.c:4914 Code: 41 80 3c 04 00 74 0a e8 90 d0 9b f7 48 8b 7c 24 08 48 8b 07 48 89 44 24 10 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 64 d0 9b f7 48 8b 44 24 18 49 39 06 RSP: 0018:ffffc900047374e0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 1ffff1100fdf8f33 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807efc78c0 RBP: ffffc900047375d0 R08: 0000000000000003 R09: fffff520008e6e8c R10: dffffc0000000000 R11: fffff520008e6e8c R12: 1ffff1100fdf8f18 R13: ffff88807efc7998 R14: 0000000000000000 R15: ffff88807efc7930 FS: 0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002a80 CR3: 0000000022f62000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> addrconf_ifdown+0x15d/0x1bd0 net/ipv6/addrconf.c:3856 addrconf_notify+0x3cb/0x1020 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline] call_netdevice_notifiers net/core/dev.c:2046 [inline] unregister_netdevice_many_notify+0xd81/0x1c40 net/core/dev.c:11352...
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H