In the Linux kernel, the following vulnerability has been resolved: bpf: Fix racing between bpf_timer_cancel_and_free and bpf_timer_cancel The following race is possible between bpf_timer_cancel_and_free and bpf_timer_cancel. It will lead a UAF on the timer->timer. bpf_timer_cancel(); spin_lock(); t = timer->time; spin_unlock(); bpf_timer_cancel_and_free(); spin_lock(); t = timer->timer; timer->timer = NULL; spin_unlock(); hrtimer_cancel(&t->timer); kfree(t); /* UAF on t */ hrtimer_cancel(&t->timer); In bpf_timer_cancel_and_free, this patch frees the timer->timer after a rcu grace period. This requires a rcu_head addition to the struct bpf_hrtimer. Another kfree(t) happens in bpf_timer_init, this does not need a kfree_rcu because it is still under the spin_lock and timer->timer has not been visible by others yet. In bpf_timer_cancel, rcu_read_lock() is added because this helper can be used in a non rcu critical section context (e.g. from a sleepable bpf prog). Other timer->timer usages in helpers.c have been audited, bpf_timer_cancel() is the only place where timer->timer is used outside of the spin_lock. Another solution considered is to mark a t->flag in bpf_timer_cancel and clear it after hrtimer_cancel() is done. In bpf_timer_cancel_and_free, it busy waits for the flag to be cleared before kfree(t). This patch goes with a straight forward solution and frees timer->timer after a rcu grace period.
Find out more about CVE-2024-26737 from the MITRE-CVE dictionary and NIST NVD
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| Product Name | Status | Defect | Fixed | Downloads |
|---|---|---|---|---|
| Linux | ||||
| Wind River Linux LTS 17 | Requires LTSS | -- | -- | -- |
| Wind River Linux 8 | Requires LTSS | -- | -- | -- |
| Wind River Linux 9 | Requires LTSS | -- | -- | -- |
| Wind River Linux 7 | Requires LTSS | -- | -- | -- |
| Wind River Linux LTS 21 | Investigate | -- | -- | -- |
| Wind River Linux LTS 22 | Fixed |
LIN1022-7387 |
10.22.33.16 | -- |
| Wind River Linux LTS 18 | Requires LTSS | -- | -- | -- |
| Wind River Linux LTS 19 | Investigate | -- | -- | -- |
| Wind River Linux CD release | N/A | -- | -- | -- |
| Wind River Linux 6 | Requires LTSS | -- | -- | -- |
| Wind River Linux LTS 23 | Fixed |
LIN1023-4556 |
10.23.30.9 | -- |
| VxWorks | ||||
| VxWorks 7 | Not Vulnerable | -- | -- | -- |
| VxWorks 6.9 | Not Vulnerable | -- | -- | -- |
| Helix Virtualization Platform Cert Edition | ||||
| Helix Virtualization Platform Cert Edition | Not Vulnerable | -- | -- | -- |
| Product Name | Status | Defect | Fixed | Downloads |
|---|
