CVE-2024-36013
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.47% probability · 40th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/4d7b41c0e43995b0e992b9f8903109275744b658Patch
- https://git.kernel.org/stable/c/826af9d2f69567c646ff46d10393d47e30ad23c6Patch
- https://git.kernel.org/stable/c/8629a65a48890769c47ebc9b6e57c02a80a8975e
- https://git.kernel.org/stable/c/cfe560c7050bfb37b0d2491bbe7cd8b59e77fdc5Patch
- http://www.openwall.com/lists/oss-security/2024/05/30/1Issue Tracking, Mailing List
- http://www.openwall.com/lists/oss-security/2024/05/30/2Issue Tracking, Mailing List
- https://git.kernel.org/stable/c/4d7b41c0e43995b0e992b9f8903109275744b658Patch
- https://git.kernel.org/stable/c/826af9d2f69567c646ff46d10393d47e30ad23c6Patch
- https://git.kernel.org/stable/c/cfe560c7050bfb37b0d2491bbe7cd8b59e77fdc5Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.