CVE-2024-36013

Summary

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

Bluetooth: L2CAP: Fix slab-use-after-free in l2cap_connect()

Extend a critical section to prevent chan from early freeing. Also make the l2cap_connect() return type void. Nothing is using the returned value but it is ugly to return a potentially freed pointer. Making it void will help with backports because earlier kernels did use the return value. Now the compile will break for kernels where this patch is not a complete fix.

Call stack summary:

[use] l2cap_bredr_sig_cmd l2cap_connect ┌ mutex_lock(&conn->chan_lock); │ chan = pchan->ops->new_connection(pchan); <- alloc chan │ __l2cap_chan_add(conn, chan); │ l2cap_chan_hold(chan); │ list_add(&chan->list, &conn->chan_l); … (1) └ mutex_unlock(&conn->chan_lock); chan->conf_state … (4) <- use after free

[free] l2cap_conn_del ┌ mutex_lock(&conn->chan_lock); │ foreach chan in conn->chan_l: … (2) │ l2cap_chan_put(chan); │ l2cap_chan_destroy │ kfree(chan) … (3) <- chan freed └ mutex_unlock(&conn->chan_lock);

================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect+0xa67/0x11a0 net/bluetooth/l2cap_core.c:4260 Read of size 8 at addr ffff88810bf040a0 by task kworker/u3:1/311

Affected Software

VendorProductVersion RangeStatus
LinuxLinux73ffa904b78287f6acf8797e040150aa26a4af4a < cfe560c7050bfb37b0d2491bbe7cd8b59e77fdc5affected
LinuxLinux73ffa904b78287f6acf8797e040150aa26a4af4a < 826af9d2f69567c646ff46d10393d47e30ad23c6affected
LinuxLinux73ffa904b78287f6acf8797e040150aa26a4af4a < 4d7b41c0e43995b0e992b9f8903109275744b658affected
LinuxLinux3.0affected
LinuxLinux0 < 3.0unaffected
LinuxLinux6.6.32 <= 6.6.*unaffected
LinuxLinux6.8.11 <= 6.8.*unaffected
LinuxLinux6.9 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

CVE Program Container

Additional References

References