Red Hat Security Advisory: kernel security update

Important

In the Linux kernel, the following vulnerability has been resolved: net: usb: smsc75xx: Limit packet length to skb->len Packet length retrieved from skb data may be larger than the actual socket buffer length (up to 9026 bytes). In such case the cloned skb passed up the network stack will leak kernel memory contents.

CWE-125 - Out-of-bounds Read

A use-after-free (UAF) vulnerability was found in the Linux kernel's net/sched subsystem, specifically in the Credit-Based Shaper (CBS) qdisc implementation (sch_cbs). The vulnerability occurs because the CBS qdisc's reset function (qdisc_reset_queue()) only resets its internal queue but fails to reset its child qdisc recursively. As a result, a mismatch in queue length (qlen) occurs between CBS and its children during interface resets, eventually allowing attackers to trigger UAF on a parent HFSC scheduler.

CWE-416 - Use After Free

In the Linux kernel, the following vulnerability has been resolved: idpf: convert control queue mutex to a spinlock With VIRTCHNL2_CAP_MACFILTER enabled, the following warning is generated on module load: [ 324.701677] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:578 [ 324.701684] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1582, name: NetworkManager [ 324.701689] preempt_count: 201, expected: 0 [ 324.701693] RCU nest depth: 0, expected: 0 [ 324.701697] 2 locks held by NetworkManager/1582: [ 324.701702] #0: ffffffff9f7be770 (rtnl_mutex){....}-{3:3}, at: rtnl_newlink+0x791/0x21e0 [ 324.701730] #1: ff1100216c380368 (_xmit_ETHER){....}-{2:2}, at: __dev_open+0x3f0/0x870 [ 324.701749] Preemption disabled at: [ 324.701752] [<ffffffff9cd23b9d>] __dev_open+0x3dd/0x870 [ 324.701765] CPU: 30 UID: 0 PID: 1582 Comm: NetworkManager Not tainted 6.15.0-rc5+ #2 PREEMPT(voluntary) [ 324.701771] Hardware name: Intel Corporation M50FCP2SBSTD/M50FCP2SBSTD, BIOS SE5C741.86B.01.01.0001.2211140926 11/14/2022 [ 324.701774] Call Trace: [ 324.701777] <TASK> [ 324.701779] dump_stack_lvl+0x5d/0x80 [ 324.701788] ? __dev_open+0x3dd/0x870 [ 324.701793] __might_resched.cold+0x1ef/0x23d <..> [ 324.701818] __mutex_lock+0x113/0x1b80 <..> [ 324.701917] idpf_ctlq_clean_sq+0xad/0x4b0 [idpf] [ 324.701935] ? kasan_save_track+0x14/0x30 [ 324.701941] idpf_mb_clean+0x143/0x380 [idpf] <..> [ 324.701991] idpf_send_mb_msg+0x111/0x720 [idpf] [ 324.702009] idpf_vc_xn_exec+0x4cc/0x990 [idpf] [ 324.702021] ? rcu_is_watching+0x12/0xc0 [ 324.702035] idpf_add_del_mac_filters+0x3ed/0xb50 [idpf] <..> [ 324.702122] __hw_addr_sync_dev+0x1cf/0x300 [ 324.702126] ? find_held_lock+0x32/0x90 [ 324.702134] idpf_set_rx_mode+0x317/0x390 [idpf] [ 324.702152] __dev_open+0x3f8/0x870 [ 324.702159] ? __pfx___dev_open+0x10/0x10 [ 324.702174] __dev_change_flags+0x443/0x650 <..> [ 324.702208] netif_change_flags+0x80/0x160 [ 324.702218] do_setlink.isra.0+0x16a0/0x3960 <..> [ 324.702349] rtnl_newlink+0x12fd/0x21e0 The sequence is as follows: rtnl_newlink()-> __dev_change_flags()-> __dev_open()-> dev_set_rx_mode() - > # disables BH and grabs "dev->addr_list_lock" idpf_set_rx_mode() -> # proceed only if VIRTCHNL2_CAP_MACFILTER is ON __dev_uc_sync() -> idpf_add_mac_filter -> idpf_add_del_mac_filters -> idpf_send_mb_msg() -> idpf_mb_clean() -> idpf_ctlq_clean_sq() # mutex_lock(cq_lock) Fix by converting cq_lock to a spinlock. All operations under the new lock are safe except freeing the DMA memory, which may use vunmap(). Fix by requesting a contiguous physical memory for the DMA mapping.

CWE-767 - Access to Critical Private Variable via Public Method

In the Linux kernel, the following vulnerability has been resolved: drm/gem: Acquire references on GEM handles for framebuffers A GEM handle can be released while the GEM buffer object is attached to a DRM framebuffer. This leads to the release of the dma-buf backing the buffer object, if any. [1] Trying to use the framebuffer in further mode-setting operations leads to a segmentation fault. Most easily happens with driver that use shadow planes for vmap-ing the dma-buf during a page flip. An example is shown below. [ 156.791968] ------------[ cut here ]------------ [ 156.796830] WARNING: CPU: 2 PID: 2255 at drivers/dma-buf/dma-buf.c:1527 dma_buf_vmap+0x224/0x430 [...] [ 156.942028] RIP: 0010:dma_buf_vmap+0x224/0x430 [ 157.043420] Call Trace: [ 157.045898] <TASK> [ 157.048030] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.052436] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.056836] ? show_trace_log_lvl+0x1af/0x2c0 [ 157.061253] ? drm_gem_shmem_vmap+0x74/0x710 [ 157.065567] ? dma_buf_vmap+0x224/0x430 [ 157.069446] ? __warn.cold+0x58/0xe4 [ 157.073061] ? dma_buf_vmap+0x224/0x430 [ 157.077111] ? report_bug+0x1dd/0x390 [ 157.080842] ? handle_bug+0x5e/0xa0 [ 157.084389] ? exc_invalid_op+0x14/0x50 [ 157.088291] ? asm_exc_invalid_op+0x16/0x20 [ 157.092548] ? dma_buf_vmap+0x224/0x430 [ 157.096663] ? dma_resv_get_singleton+0x6d/0x230 [ 157.101341] ? __pfx_dma_buf_vmap+0x10/0x10 [ 157.105588] ? __pfx_dma_resv_get_singleton+0x10/0x10 [ 157.110697] drm_gem_shmem_vmap+0x74/0x710 [ 157.114866] drm_gem_vmap+0xa9/0x1b0 [ 157.118763] drm_gem_vmap_unlocked+0x46/0xa0 [ 157.123086] drm_gem_fb_vmap+0xab/0x300 [ 157.126979] drm_atomic_helper_prepare_planes.part.0+0x487/0xb10 [ 157.133032] ? lockdep_init_map_type+0x19d/0x880 [ 157.137701] drm_atomic_helper_commit+0x13d/0x2e0 [ 157.142671] ? drm_atomic_nonblocking_commit+0xa0/0x180 [ 157.147988] drm_mode_atomic_ioctl+0x766/0xe40 [...] [ 157.346424] ---[ end trace 0000000000000000 ]--- Acquiring GEM handles for the framebuffer's GEM buffer objects prevents this from happening. The framebuffer's cleanup later puts the handle references. Commit 1a148af06000 ("drm/gem-shmem: Use dma_buf from GEM object instance") triggers the segmentation fault easily by using the dma-buf field more widely. The underlying issue with reference counting has been present before. v2: - acquire the handle instead of the BO (Christian) - fix comment style (Christian) - drop the Fixes tag (Christian) - rename err_ gotos - add missing Link tag

CWE-416 - Use After Free