CVE-2024-46785

/// Technical description

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

eventfs: Use list_del_rcu() for SRCU protected list variable

Chi Zhiling reported:

We found a null pointer accessing in tracefs[1], the reason is that the

variable 'ei_child' is set to LIST_POISON1, that means the list was

removed in eventfs_remove_rec. so when access the ei_child->is_freed, the

panic triggered.

by the way, the following script can reproduce this panic

loop1 (){

while true

do

echo "p:kp submit_bio" > /sys/kernel/debug/tracing/kprobe_events

echo "" > /sys/kernel/debug/tracing/kprobe_events

done

}

loop2 (){

while true

do

tree /sys/kernel/debug/tracing/events/kprobes/

done

}

loop1 &

loop2

[1]:

[ 1147.959632][T17331] Unable to handle kernel paging request at virtual address dead000000000150

[ 1147.968239][T17331] Mem abort info:

[ 1147.971739][T17331] ESR = 0x0000000096000004

[ 1147.976172][T17331] E

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References