7.8

CVE-2024-50126

In the Linux kernel, the following vulnerability has been resolved:

net: sched: use RCU read-side critical section in taprio_dump()

Fix possible use-after-free in 'taprio_dump()' by adding RCU
read-side critical section there. Never seen on x86 but
found on a KASAN-enabled arm64 system when investigating
https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa:

[T15862] BUG: KASAN: slab-use-after-free in taprio_dump+0xa0c/0xbb0
[T15862] Read of size 4 at addr ffff0000d4bb88f8 by task repro/15862
[T15862]
[T15862] CPU: 0 UID: 0 PID: 15862 Comm: repro Not tainted 6.11.0-rc1-00293-gdefaf1a2113a-dirty #2
[T15862] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-20240524-5.fc40 05/24/2024
[T15862] Call trace:
[T15862]  dump_backtrace+0x20c/0x220
[T15862]  show_stack+0x2c/0x40
[T15862]  dump_stack_lvl+0xf8/0x174
[T15862]  print_report+0x170/0x4d8
[T15862]  kasan_report+0xb8/0x1d4
[T15862]  __asan_report_load4_noabort+0x20/0x2c
[T15862]  taprio_dump+0xa0c/0xbb0
[T15862]  tc_fill_qdisc+0x540/0x1020
[T15862]  qdisc_notify.isra.0+0x330/0x3a0
[T15862]  tc_modify_qdisc+0x7b8/0x1838
[T15862]  rtnetlink_rcv_msg+0x3c8/0xc20
[T15862]  netlink_rcv_skb+0x1f8/0x3d4
[T15862]  rtnetlink_rcv+0x28/0x40
[T15862]  netlink_unicast+0x51c/0x790
[T15862]  netlink_sendmsg+0x79c/0xc20
[T15862]  __sock_sendmsg+0xe0/0x1a0
[T15862]  ____sys_sendmsg+0x6c0/0x840
[T15862]  ___sys_sendmsg+0x1ac/0x1f0
[T15862]  __sys_sendmsg+0x110/0x1d0
[T15862]  __arm64_sys_sendmsg+0x74/0xb0
[T15862]  invoke_syscall+0x88/0x2e0
[T15862]  el0_svc_common.constprop.0+0xe4/0x2a0
[T15862]  do_el0_svc+0x44/0x60
[T15862]  el0_svc+0x50/0x184
[T15862]  el0t_64_sync_handler+0x120/0x12c
[T15862]  el0t_64_sync+0x190/0x194
[T15862]
[T15862] Allocated by task 15857:
[T15862]  kasan_save_stack+0x3c/0x70
[T15862]  kasan_save_track+0x20/0x3c
[T15862]  kasan_save_alloc_info+0x40/0x60
[T15862]  __kasan_kmalloc+0xd4/0xe0
[T15862]  __kmalloc_cache_noprof+0x194/0x334
[T15862]  taprio_change+0x45c/0x2fe0
[T15862]  tc_modify_qdisc+0x6a8/0x1838
[T15862]  rtnetlink_rcv_msg+0x3c8/0xc20
[T15862]  netlink_rcv_skb+0x1f8/0x3d4
[T15862]  rtnetlink_rcv+0x28/0x40
[T15862]  netlink_unicast+0x51c/0x790
[T15862]  netlink_sendmsg+0x79c/0xc20
[T15862]  __sock_sendmsg+0xe0/0x1a0
[T15862]  ____sys_sendmsg+0x6c0/0x840
[T15862]  ___sys_sendmsg+0x1ac/0x1f0
[T15862]  __sys_sendmsg+0x110/0x1d0
[T15862]  __arm64_sys_sendmsg+0x74/0xb0
[T15862]  invoke_syscall+0x88/0x2e0
[T15862]  el0_svc_common.constprop.0+0xe4/0x2a0
[T15862]  do_el0_svc+0x44/0x60
[T15862]  el0_svc+0x50/0x184
[T15862]  el0t_64_sync_handler+0x120/0x12c
[T15862]  el0t_64_sync+0x190/0x194
[T15862]
[T15862] Freed by task 6192:
[T15862]  kasan_save_stack+0x3c/0x70
[T15862]  kasan_save_track+0x20/0x3c
[T15862]  kasan_save_free_info+0x4c/0x80
[T15862]  poison_slab_object+0x110/0x160
[T15862]  __kasan_slab_free+0x3c/0x74
[T15862]  kfree+0x134/0x3c0
[T15862]  taprio_free_sched_cb+0x18c/0x220
[T15862]  rcu_core+0x920/0x1b7c
[T15862]  rcu_core_si+0x10/0x1c
[T15862]  handle_softirqs+0x2e8/0xd64
[T15862]  __do_softirq+0x14/0x20
Data is provided by the National Vulnerability Database (NVD)
LinuxLinux Kernel Version >= 6.1 < 6.6.59
LinuxLinux Kernel Version >= 6.7 < 6.11.6
LinuxLinux Kernel Version6.12 Updaterc1
LinuxLinux Kernel Version6.12 Updaterc2
LinuxLinux Kernel Version6.12 Updaterc3
LinuxLinux Kernel Version6.12 Updaterc4
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Type Source Score Percentile
EPSS FIRST.org 0.05% 0.143
CVSS Metriken
Source Base Score Exploit Score Impact Score Vector string
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
134c704f-9b21-4f2e-91b3-4a467353bcc0 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.