CVE-2024-50126: net: sched: use RCU read-side critical section in taprio_dump()
In the Linux kernel, the following vulnerability has been resolved:
net: sched: use RCU read-side critical section in tapriodump()
Fix possible use-after-free in 'tapriodump()' by adding RCU read-side critical section there. Never seen on x86 but found on a KASAN-enabled arm64 system when investigating <a href="https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa">https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa</a>:
[T15862] BUG: KASAN: slab-use-after-free in tapriodump+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] dumpbacktrace+0x20c/0x220 [T15862] showstack+0x2c/0x40 [T15862] dumpstacklvl+0xf8/0x174 [T15862] printreport+0x170/0x4d8 [T15862] kasanreport+0xb8/0x1d4 [T15862] asanreportload4noabort+0x20/0x2c [T15862] tapriodump+0xa0c/0xbb0 [T15862] tcfillqdisc+0x540/0x1020 [T15862] qdiscnotify.isra.0+0x330/0x3a0 [T15862] tcmodifyqdisc+0x7b8/0x1838 [T15862] rtnetlinkrcvmsg+0x3c8/0xc20 [T15862] netlinkrcvskb+0x1f8/0x3d4 [T15862] rtnetlinkrcv+0x28/0x40 [T15862] netlinkunicast+0x51c/0x790 [T15862] netlinksendmsg+0x79c/0xc20 [T15862] socksendmsg+0xe0/0x1a0 [T15862] syssendmsg+0x6c0/0x840 [T15862] syssendmsg+0x1ac/0x1f0 [T15862] syssendmsg+0x110/0x1d0 [T15862] arm64syssendmsg+0x74/0xb0 [T15862] invokesyscall+0x88/0x2e0 [T15862] el0svccommon.constprop.0+0xe4/0x2a0 [T15862] doel0svc+0x44/0x60 [T15862] el0svc+0x50/0x184 [T15862] el0t64synchandler+0x120/0x12c [T15862] el0t64sync+0x190/0x194 [T15862] [T15862] Allocated by task 15857: [T15862] kasansavestack+0x3c/0x70 [T15862] kasansavetrack+0x20/0x3c [T15862] kasansaveallocinfo+0x40/0x60 [T15862] kasankmalloc+0xd4/0xe0 [T15862] kmalloccachenoprof+0x194/0x334 [T15862] tapriochange+0x45c/0x2fe0 [T15862] tcmodifyqdisc+0x6a8/0x1838 [T15862] rtnetlinkrcvmsg+0x3c8/0xc20 [T15862] netlinkrcvskb+0x1f8/0x3d4 [T15862] rtnetlinkrcv+0x28/0x40 [T15862] netlinkunicast+0x51c/0x790 [T15862] netlinksendmsg+0x79c/0xc20 [T15862] socksendmsg+0xe0/0x1a0 [T15862] syssendmsg+0x6c0/0x840 [T15862] syssendmsg+0x1ac/0x1f0 [T15862] syssendmsg+0x110/0x1d0 [T15862] arm64syssendmsg+0x74/0xb0 [T15862] invokesyscall+0x88/0x2e0 [T15862] el0svccommon.constprop.0+0xe4/0x2a0 [T15862] doel0svc+0x44/0x60 [T15862] el0svc+0x50/0x184 [T15862] el0t64synchandler+0x120/0x12c [T15862] el0t64sync+0x190/0x194 [T15862] [T15862] Freed by task 6192: [T15862] kasansavestack+0x3c/0x70 [T15862] kasansavetrack+0x20/0x3c [T15862] kasansavefreeinfo+0x4c/0x80 [T15862] poisonslabobject+0x110/0x160 [T15862] kasanslabfree+0x3c/0x74 [T15862] kfree+0x134/0x3c0 [T15862] tapriofreeschedcb+0x18c/0x220 [T15862] rcucore+0x920/0x1b7c [T15862] rcucoresi+0x10/0x1c [T15862] handlesoftirqs+0x2e8/0xd64 [T15862] dosoftirq+0x14/0x20
Other sources
In the Linux kernel, the following vulnerability has been resolved:
net: sched: use RCU read-side critical section in tapriodump()
Fix possible use-after-free in 'tapriodump()' 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 tapriodump+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] dumpbacktrace+0x20c/0x220 [T15862] showstack+0x2c/0x40 [T15862] dumpstacklvl+0xf8/0x174 [T15862] printreport+0x170/0x4d8 [T15862] kasanreport+0xb8/0x1d4 [T15862] asanreportload4noabort+0x20/0x2c [T15862] tapriodump+0xa0c/0xbb0 [T15862] tcfillqdisc+0x540/0x1020 [T15862] qdiscnotify.isra.0+0x330/0x3a0 [T15862] tcmodifyqdisc+0x7b8/0x1838 [T15862] rtnetlinkrcvmsg+0x3c8/0xc20 [T15862] netlinkrcvskb+0x1f8/0x3d4 [T15862] rtnetlinkrcv+0x28/0x40 [T15862] netlinkunicast+0x51c/0x790 [T15862] netlinksendmsg+0x79c/0xc20 [T15862] socksendmsg+0xe0/0x1a0 [T15862] syssendmsg+0x6c0/0x840 [T15862] syssendmsg+0x1ac/0x1f0 [T15862] syssendmsg+0x110/0x1d0 [T15862] arm64syssendmsg+0x74/0xb0 [T15862] invokesyscall+0x88/0x2e0 [T15862] el0svccommon.constprop.0+0xe4/0x2a0 [T15862] doel0svc+0x44/0x60 [T15862] el0svc+0x50/0x184 [T15862] el0t64synchandler+0x120/0x12c [T15862] el0t64sync+0x190/0x194 [T15862] [T15862] Allocated by task 15857: [T15862] kasansavestack+0x3c/0x70 [T15862] kasansavetrack+0x20/0x3c [T15862] kasansaveallocinfo+0x40/0x60 [T15862] kasankmalloc+0xd4/0xe0 [T15862] kmalloccachenoprof+0x194/0x334 [T15862] tapriochange+0x45c/0x2fe0 [T15862] tcmodifyqdisc+0x6a8/0x1838 [T15862] rtnetlinkrcvmsg+0x3c8/0xc20 [T15862] netlinkrcvskb+0x1f8/0x3d4 [T15862] rtnetlinkrcv+0x28/0x40 [T15862] netlinkunicast+0x51c/0x790 [T15862] netlinksendmsg+0x79c/0xc20 [T15862] socksendmsg+0xe0/0x1a0 [T15862] syssendmsg+0x6c0/0x840 [T15862] syssendmsg+0x1ac/0x1f0 [T15862] syssendmsg+0x110/0x1d0 [T15862] arm64syssendmsg+0x74/0xb0 [T15862] invokesyscall+0x88/0x2e0 [T15862] el0svccommon.constprop.0+0xe4/0x2a0 [T15862] doel0svc+0x44/0x60 [T15862] el0svc+0x50/0x184 [T15862] el0t64synchandler+0x120/0x12c [T15862] el0t64sync+0x190/0x194 [T15862] [T15862] Freed by task 6192: [T15862] kasansavestack+0x3c/0x70 [T15862] kasansavetrack+0x20/0x3c [T15862] kasansavefreeinfo+0x4c/0x80 [T15862] poisonslabobject+0x110/0x160 [T15862] kasanslabfree+0x3c/0x74 [T15862] kfree+0x134/0x3c0 [T15862] tapriofreeschedcb+0x18c/0x220 [T15862] rcucore+0x920/0x1b7c [T15862] rcucoresi+0x10/0x1c [T15862] handlesoftirqs+0x2e8/0xd64 [T15862] dosoftirq+0x14/0x20
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.133-1Fixed in 6.12.21-1Fixed in 6.12.22-1 - Upgrade
Upgrade
debian/linux-6.1to a version that resolves this vulnerability.Fixed in 6.1.129-1~deb11u1 - Configuration
Fix the possible use-after-free in taprio_dump() by adding an RCU read-side critical section in net/sched (taprio_dump()).
Linux kernel net/sched taprio_dump() RCU read-side critical section = add RCU read-side critical section around taprio_dump() to prevent use-after-free
Event History
Frequently Asked Questions
What is the severity of CVE-2024-50126?
CVE-2024-50126 is considered to have a moderate severity due to the possibility of a use-after-free condition.
How do I fix CVE-2024-50126?
To fix CVE-2024-50126, update the Linux kernel to the latest stable version that includes the patch.
Which versions of the Linux kernel are affected by CVE-2024-50126?
CVE-2024-50126 affects Linux kernel versions from 6.1 to 6.6.59 and specific release candidates from 6.12.
Is CVE-2024-50126 exploitable on all architectures?
CVE-2024-50126 has not been seen on x86 but has been found on KASAN-enabled arm64 systems.
What components of the Linux kernel are impacted by CVE-2024-50126?
CVE-2024-50126 impacts the networking component, specifically the scheduling functionality in taprio_dump().