Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject sleepable BPF_LSM_CGROUP programs at load time The cgroup shim runs under rcu_read_lock_dont_migrate(), so we should not attach any sleepable BPF programs there. Add support to the verifier to explicitly reject attempts to load sleepable BPF programs destined for LSM cgroup attachment. Without this, we get the following splat from a BPF_LSM_CGROUP program marked BPF_F_SLEEPABLE attached to file_open when it calls bpf_get_dentry_xattr(): BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load preempt_count: 0, expected: 0 RCU nest depth: 2, expected: 0 Call Trace: down_read+0x76/0x480 ext4_xattr_get+0x11f/0x700 __vfs_getxattr+0xf0/0x150 bpf_get_dentry_xattr+0xbb/0xf0 bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85 __cgroup_bpf_run_lsm_current+0x326/0x840 bpf_trampoline_6442534646+0x62/0x14d security_file_open+0x34/0x60 do_dentry_open+0x340/0x1260 vfs_open+0x7a/0x440 path_openat+0x1bac/0x30a0 libbpf provides a .s named section variant for every sleepable program type except lsm_cgroup, reflecting that per-cgroup LSM programs are intended to only run in a non-sleepable context. The above splat was obtained by bypassing libbpf by using bpf(2) directly.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e before f0a49d16804d319774388a32d8cdcef319a9e481; affected 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e before 4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d; affected 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e before b4059a1f57eff3e206d44697f64ad81076512760; affected 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e before be9eaf2bb5db4ad3de61ef739fd268fd7f135737; affected 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e before 5b038319be442c620f774e6fc9e9283deeca1c75 |
| Linux / Linux | affected 6.0; unaffected 0 before 6.0; unaffected 6.6.160 through 6.6.*; unaffected 6.12.114 through 6.12.*; unaffected 6.18.57 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/f0a49d16804d319774388a32d8cdcef319a9e481
- https://git.kernel.org/stable/c/4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d
- https://git.kernel.org/stable/c/b4059a1f57eff3e206d44697f64ad81076512760
- https://git.kernel.org/stable/c/be9eaf2bb5db4ad3de61ef739fd268fd7f135737
- https://git.kernel.org/stable/c/5b038319be442c620f774e6fc9e9283deeca1c75
ADP enrichment
No English description supplied.
No references supplied.