A flaw use after free in the Linux kernel Management Component Transport Protocol (MCTP) subsystem was found in the way user triggers cancel_work_sync after the unregister_netdev during removing device. A local user could use this flaw to crash the system or escalate their privileges on the system. It is actual from Linux Kernel 5.17-rc1 (when mctp-serial.c introduced) till 5.17-rc5.

An integer overflow flaw was found in the Linux kernel’s virtio device driver code in the way a user triggers the vhost_vdpa_config_validate function. This flaw allows a local user to crash or potentially escalate their privileges on the system.

Buffer overflow in the kvm_vcpu_ioctl_x86_setup_mce function in arch/x86/kvm/x86.c in the KVM subsystem in the Linux kernel before 2.6.32-rc7 allows local users to cause a denial of service (memory corruption) or possibly gain privileges via a KVM_X86_SETUP_MCE IOCTL request that specifies a large number of Machine Check Exception (MCE) banks.

IBM QRadar SIEM 7.3, 7.4, and 7.5 is vulnerable to local privilege escalation if this could be combined with other unknown vulnerabilities then privilege escalation could be performed. IBM X-Force ID: 216111.

The ip_cmsg_recv_checksum function in net/ipv4/ip_sockglue.c in the Linux kernel before 4.10.1 has incorrect expectations about skb data layout, which allows local users to cause a denial of service (buffer over-read) or possibly have unspecified other impact via crafted system calls, as demonstrated by use of the MSG_MORE flag in conjunction with loopback UDP transmission.

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 binaries load shared libraries from an untrusted path potentially giving low privilege user full access to root by loading a malicious shared library. IBM X-Force ID: 158014.

A use-after-free exists in the Linux Kernel in tc_new_tfilter that could allow a local attacker to gain privilege escalation. The exploit requires unprivileged user namespaces. We recommend upgrading past commit 04c2a47ffb13c29778e2a14e414ad4cb5a5db4b5

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix out-of-bounds write warning Check the ring type value to fix the out-of-bounds write warning

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 is vulnerable to a buffer overflow, which could allow an authenticated local attacker to execute arbitrary code on the system as root. IBM X-ForceID: 155894.

In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to cover read extent cache access with lock syzbot reports a f2fs bug as below: BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097 CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 do_read_inode fs/f2fs/inode.c:509 [inline] f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584 do_handle_to_path fs/fhandle.c:155 [inline] handle_to_path fs/fhandle.c:210 [inline] do_handle_open+0x495/0x650 fs/fhandle.c:226 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f We missed to cover sanity_check_extent_cache() w/ extent cache lock, so, below race case may happen, result in use after free issue. - f2fs_iget - do_read_inode - f2fs_init_read_extent_tree : add largest extent entry in to cache - shrink - f2fs_shrink_read_extent_tree - __shrink_extent_tree - __detach_extent_node : drop largest extent entry - sanity_check_extent_cache : access et->largest w/o lock let's refactor sanity_check_extent_cache() to avoid extent cache access and call it before f2fs_init_read_extent_tree() to fix this issue.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC syzbot reports a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/inline.c:258! CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0 RIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258 Call Trace: f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834 f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline] __f2fs_write_data_pages fs/f2fs/data.c:3288 [inline] f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315 do_writepages+0x35b/0x870 mm/page-writeback.c:2612 __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650 writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941 wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117 wb_do_writeback fs/fs-writeback.c:2264 [inline] wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The root cause is: inline_data inode can be fuzzed, so that there may be valid blkaddr in its direct node, once f2fs triggers background GC to migrate the block, it will hit f2fs_bug_on() during dirty page writeback. Let's add sanity check on F2FS_INLINE_DATA flag in inode during GC, so that, it can forbid migrating inline_data inode's data block for fixing.

A flaw was found in the Linux kernel. A use-after-free vulnerability in the NFC stack can lead to a threat to confidentiality, integrity, and system availability.

In the Linux kernel, the following vulnerability has been resolved: igc: Fix use-after-free error during reset Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring. Failure to do so can cause invalid memory accesses. If igc_poll() runs while the controller is being reset this can lead to the driver try to free a skb that was already freed. Log message: [ 101.525242] refcount_t: underflow; use-after-free. [ 101.525251] WARNING: CPU: 1 PID: 646 at lib/refcount.c:28 refcount_warn_saturate+0xab/0xf0 [ 101.525259] Modules linked in: sch_etf(E) sch_mqprio(E) rfkill(E) intel_rapl_msr(E) intel_rapl_common(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) binfmt_misc(E) kvm_intel(E) kvm(E) irqbypass(E) crc32_pclmul(E) ghash_clmulni_intel(E) aesni_intel(E) mei_wdt(E) libaes(E) crypto_simd(E) cryptd(E) glue_helper(E) snd_hda_codec_hdmi(E) rapl(E) intel_cstate(E) snd_hda_intel(E) snd_intel_dspcfg(E) sg(E) soundwire_intel(E) intel_uncore(E) at24(E) soundwire_generic_allocation(E) iTCO_wdt(E) soundwire_cadence(E) intel_pmc_bxt(E) serio_raw(E) snd_hda_codec(E) iTCO_vendor_support(E) watchdog(E) snd_hda_core(E) snd_hwdep(E) snd_soc_core(E) snd_compress(E) snd_pcsp(E) soundwire_bus(E) snd_pcm(E) evdev(E) snd_timer(E) mei_me(E) snd(E) soundcore(E) mei(E) configfs(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) sd_mod(E) t10_pi(E) crc_t10dif(E) crct10dif_generic(E) i915(E) ahci(E) libahci(E) ehci_pci(E) igb(E) xhci_pci(E) ehci_hcd(E) [ 101.525303] drm_kms_helper(E) dca(E) xhci_hcd(E) libata(E) crct10dif_pclmul(E) cec(E) crct10dif_common(E) tsn(E) igc(E) e1000e(E) ptp(E) i2c_i801(E) crc32c_intel(E) psmouse(E) i2c_algo_bit(E) i2c_smbus(E) scsi_mod(E) lpc_ich(E) pps_core(E) usbcore(E) drm(E) button(E) video(E) [ 101.525318] CPU: 1 PID: 646 Comm: irq/37-enp7s0-T Tainted: G E 5.10.30-rt37-tsn1-rt-ipipe #ipipe [ 101.525320] Hardware name: SIEMENS AG SIMATIC IPC427D/A5E31233588, BIOS V17.02.09 03/31/2017 [ 101.525322] RIP: 0010:refcount_warn_saturate+0xab/0xf0 [ 101.525325] Code: 05 31 48 44 01 01 e8 f0 c6 42 00 0f 0b c3 80 3d 1f 48 44 01 00 75 90 48 c7 c7 78 a8 f3 a6 c6 05 0f 48 44 01 01 e8 d1 c6 42 00 <0f> 0b c3 80 3d fe 47 44 01 00 0f 85 6d ff ff ff 48 c7 c7 d0 a8 f3 [ 101.525327] RSP: 0018:ffffbdedc0917cb8 EFLAGS: 00010286 [ 101.525329] RAX: 0000000000000000 RBX: ffff98fd6becbf40 RCX: 0000000000000001 [ 101.525330] RDX: 0000000000000001 RSI: ffffffffa6f2700c RDI: 00000000ffffffff [ 101.525332] RBP: ffff98fd6becc14c R08: ffffffffa7463d00 R09: ffffbdedc0917c50 [ 101.525333] R10: ffffffffa74c3578 R11: 0000000000000034 R12: 00000000ffffff00 [ 101.525335] R13: ffff98fd6b0b1000 R14: 0000000000000039 R15: ffff98fd6be35c40 [ 101.525337] FS: 0000000000000000(0000) GS:ffff98fd6e240000(0000) knlGS:0000000000000000 [ 101.525339] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 101.525341] CR2: 00007f34135a3a70 CR3: 0000000150210003 CR4: 00000000001706e0 [ 101.525343] Call Trace: [ 101.525346] sock_wfree+0x9c/0xa0 [ 101.525353] unix_destruct_scm+0x7b/0xa0 [ 101.525358] skb_release_head_state+0x40/0x90 [ 101.525362] skb_release_all+0xe/0x30 [ 101.525364] napi_consume_skb+0x57/0x160 [ 101.525367] igc_poll+0xb7/0xc80 [igc] [ 101.525376] ? sched_clock+0x5/0x10 [ 101.525381] ? sched_clock_cpu+0xe/0x100 [ 101.525385] net_rx_action+0x14c/0x410 [ 101.525388] __do_softirq+0xe9/0x2f4 [ 101.525391] __local_bh_enable_ip+0xe3/0x110 [ 101.525395] ? irq_finalize_oneshot.part.47+0xe0/0xe0 [ 101.525398] irq_forced_thread_fn+0x6a/0x80 [ 101.525401] irq_thread+0xe8/0x180 [ 101.525403] ? wake_threads_waitq+0x30/0x30 [ 101.525406] ? irq_thread_check_affinity+0xd0/0xd0 [ 101.525408] kthread+0x183/0x1a0 [ 101.525412] ? kthread_park+0x80/0x80 [ 101.525415] ret_from_fork+0x22/0x30

In the Linux kernel, the following vulnerability has been resolved: net/tls: Fix use-after-free after the TLS device goes down and up When a netdev with active TLS offload goes down, tls_device_down is called to stop the offload and tear down the TLS context. However, the socket stays alive, and it still points to the TLS context, which is now deallocated. If a netdev goes up, while the connection is still active, and the data flow resumes after a number of TCP retransmissions, it will lead to a use-after-free of the TLS context. This commit addresses this bug by keeping the context alive until its normal destruction, and implements the necessary fallbacks, so that the connection can resume in software (non-offloaded) kTLS mode. On the TX side tls_sw_fallback is used to encrypt all packets. The RX side already has all the necessary fallbacks, because receiving non-decrypted packets is supported. The thing needed on the RX side is to block resync requests, which are normally produced after receiving non-decrypted packets. The necessary synchronization is implemented for a graceful teardown: first the fallbacks are deployed, then the driver resources are released (it used to be possible to have a tls_dev_resync after tls_dev_del). A new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback mode. It's used to skip the RX resync logic completely, as it becomes useless, and some objects may be released (for example, resync_async, which is allocated and freed by the driver).

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Validate channel ID when processing command completions MHI reads the channel ID from the event ring element sent by the device which can be any value between 0 and 255. In order to prevent any out of bound accesses, add a check against the maximum number of channels supported by the controller and those channels not configured yet so as to skip processing of that event ring element.

In the Linux kernel, the following vulnerability has been resolved: iio: mma8452: Fix trigger reference couting The mma8452 driver directly assigns a trigger to the struct iio_dev. The IIO core when done using this trigger will call `iio_trigger_put()` to drop the reference count by 1. Without the matching `iio_trigger_get()` in the driver the reference count can reach 0 too early, the trigger gets freed while still in use and a use-after-free occurs. Fix this by getting a reference to the trigger before assigning it to the IIO device.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free of encap entry in neigh update handler Function mlx5e_rep_neigh_update() wasn't updated to accommodate rtnl lock removal from TC filter update path and properly handle concurrent encap entry insertion/deletion which can lead to following use-after-free: [23827.464923] ================================================================== [23827.469446] BUG: KASAN: use-after-free in mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.470971] Read of size 4 at addr ffff8881d132228c by task kworker/u20:6/21635 [23827.472251] [23827.472615] CPU: 9 PID: 21635 Comm: kworker/u20:6 Not tainted 5.13.0-rc3+ #5 [23827.473788] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [23827.475639] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core] [23827.476731] Call Trace: [23827.477260] dump_stack+0xbb/0x107 [23827.477906] print_address_description.constprop.0+0x18/0x140 [23827.478896] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.479879] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.480905] kasan_report.cold+0x7c/0xd8 [23827.481701] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.482744] kasan_check_range+0x145/0x1a0 [23827.493112] mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.494054] ? mlx5e_tc_tun_encap_info_equal_generic+0x140/0x140 [mlx5_core] [23827.495296] mlx5e_rep_neigh_update+0x41e/0x5e0 [mlx5_core] [23827.496338] ? mlx5e_rep_neigh_entry_release+0xb80/0xb80 [mlx5_core] [23827.497486] ? read_word_at_a_time+0xe/0x20 [23827.498250] ? strscpy+0xa0/0x2a0 [23827.498889] process_one_work+0x8ac/0x14e0 [23827.499638] ? lockdep_hardirqs_on_prepare+0x400/0x400 [23827.500537] ? pwq_dec_nr_in_flight+0x2c0/0x2c0 [23827.501359] ? rwlock_bug.part.0+0x90/0x90 [23827.502116] worker_thread+0x53b/0x1220 [23827.502831] ? process_one_work+0x14e0/0x14e0 [23827.503627] kthread+0x328/0x3f0 [23827.504254] ? _raw_spin_unlock_irq+0x24/0x40 [23827.505065] ? __kthread_bind_mask+0x90/0x90 [23827.505912] ret_from_fork+0x1f/0x30 [23827.506621] [23827.506987] Allocated by task 28248: [23827.507694] kasan_save_stack+0x1b/0x40 [23827.508476] __kasan_kmalloc+0x7c/0x90 [23827.509197] mlx5e_attach_encap+0xde1/0x1d40 [mlx5_core] [23827.510194] mlx5e_tc_add_fdb_flow+0x397/0xc40 [mlx5_core] [23827.511218] __mlx5e_add_fdb_flow+0x519/0xb30 [mlx5_core] [23827.512234] mlx5e_configure_flower+0x191c/0x4870 [mlx5_core] [23827.513298] tc_setup_cb_add+0x1d5/0x420 [23827.514023] fl_hw_replace_filter+0x382/0x6a0 [cls_flower] [23827.514975] fl_change+0x2ceb/0x4a51 [cls_flower] [23827.515821] tc_new_tfilter+0x89a/0x2070 [23827.516548] rtnetlink_rcv_msg+0x644/0x8c0 [23827.517300] netlink_rcv_skb+0x11d/0x340 [23827.518021] netlink_unicast+0x42b/0x700 [23827.518742] netlink_sendmsg+0x743/0xc20 [23827.519467] sock_sendmsg+0xb2/0xe0 [23827.520131] ____sys_sendmsg+0x590/0x770 [23827.520851] ___sys_sendmsg+0xd8/0x160 [23827.521552] __sys_sendmsg+0xb7/0x140 [23827.522238] do_syscall_64+0x3a/0x70 [23827.522907] entry_SYSCALL_64_after_hwframe+0x44/0xae [23827.523797] [23827.524163] Freed by task 25948: [23827.524780] kasan_save_stack+0x1b/0x40 [23827.525488] kasan_set_track+0x1c/0x30 [23827.526187] kasan_set_free_info+0x20/0x30 [23827.526968] __kasan_slab_free+0xed/0x130 [23827.527709] slab_free_freelist_hook+0xcf/0x1d0 [23827.528528] kmem_cache_free_bulk+0x33a/0x6e0 [23827.529317] kfree_rcu_work+0x55f/0xb70 [23827.530024] process_one_work+0x8ac/0x14e0 [23827.530770] worker_thread+0x53b/0x1220 [23827.531480] kthread+0x328/0x3f0 [23827.532114] ret_from_fork+0x1f/0x30 [23827.532785] [23827.533147] Last potentially related work creation: [23827.534007] kasan_save_stack+0x1b/0x40 [23827.534710] kasan_record_aux_stack+0xab/0xc0 [23827.535492] kvfree_call_rcu+0x31/0x7b0 [23827.536206] mlx5e_tc_del ---truncated---

In the Linux kernel, the following vulnerability has been resolved: jffs2: fix use-after-free in jffs2_clear_xattr_subsystem When we mount a jffs2 image, assume that the first few blocks of the image are normal and contain at least one xattr-related inode, but the next block is abnormal. As a result, an error is returned in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then called in jffs2_build_filesystem() and then again in jffs2_do_fill_super(). Finally we can observe the following report: ================================================================== BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac Read of size 8 at addr ffff8881243384e0 by task mount/719 Call Trace: dump_stack+0x115/0x16b jffs2_clear_xattr_subsystem+0x95/0x6ac jffs2_do_fill_super+0x84f/0xc30 jffs2_fill_super+0x2ea/0x4c0 mtd_get_sb+0x254/0x400 mtd_get_sb_by_nr+0x4f/0xd0 get_tree_mtd+0x498/0x840 jffs2_get_tree+0x25/0x30 vfs_get_tree+0x8d/0x2e0 path_mount+0x50f/0x1e50 do_mount+0x107/0x130 __se_sys_mount+0x1c5/0x2f0 __x64_sys_mount+0xc7/0x160 do_syscall_64+0x45/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Allocated by task 719: kasan_save_stack+0x23/0x60 __kasan_kmalloc.constprop.0+0x10b/0x120 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0x1c0/0x870 jffs2_alloc_xattr_ref+0x2f/0xa0 jffs2_scan_medium.cold+0x3713/0x4794 jffs2_do_mount_fs.cold+0xa7/0x2253 jffs2_do_fill_super+0x383/0xc30 jffs2_fill_super+0x2ea/0x4c0 [...] Freed by task 719: kmem_cache_free+0xcc/0x7b0 jffs2_free_xattr_ref+0x78/0x98 jffs2_clear_xattr_subsystem+0xa1/0x6ac jffs2_do_mount_fs.cold+0x5e6/0x2253 jffs2_do_fill_super+0x383/0xc30 jffs2_fill_super+0x2ea/0x4c0 [...] The buggy address belongs to the object at ffff8881243384b8 which belongs to the cache jffs2_xattr_ref of size 48 The buggy address is located 40 bytes inside of 48-byte region [ffff8881243384b8, ffff8881243384e8) [...] ================================================================== The triggering of the BUG is shown in the following stack: ----------------------------------------------------------- jffs2_fill_super jffs2_do_fill_super jffs2_do_mount_fs jffs2_build_filesystem jffs2_scan_medium jffs2_scan_eraseblock <--- ERROR jffs2_clear_xattr_subsystem <--- free jffs2_clear_xattr_subsystem <--- free again ----------------------------------------------------------- An error is returned in jffs2_do_mount_fs(). If the error is returned by jffs2_sum_init(), the jffs2_clear_xattr_subsystem() does not need to be executed. If the error is returned by jffs2_build_filesystem(), the jffs2_clear_xattr_subsystem() also does not need to be executed again. So move jffs2_clear_xattr_subsystem() from 'out_inohash' to 'out_root' to fix this UAF problem.

In the Linux kernel, the following vulnerability has been resolved: bpf: Track subprog poke descriptors correctly and fix use-after-free Subprograms are calling map_poke_track(), but on program release there is no hook to call map_poke_untrack(). However, on program release, the aux memory (and poke descriptor table) is freed even though we still have a reference to it in the element list of the map aux data. When we run map_poke_run(), we then end up accessing free'd memory, triggering KASAN in prog_array_map_poke_run(): [...] [ 402.824689] BUG: KASAN: use-after-free in prog_array_map_poke_run+0xc2/0x34e [ 402.824698] Read of size 4 at addr ffff8881905a7940 by task hubble-fgs/4337 [ 402.824705] CPU: 1 PID: 4337 Comm: hubble-fgs Tainted: G I 5.12.0+ #399 [ 402.824715] Call Trace: [ 402.824719] dump_stack+0x93/0xc2 [ 402.824727] print_address_description.constprop.0+0x1a/0x140 [ 402.824736] ? prog_array_map_poke_run+0xc2/0x34e [ 402.824740] ? prog_array_map_poke_run+0xc2/0x34e [ 402.824744] kasan_report.cold+0x7c/0xd8 [ 402.824752] ? prog_array_map_poke_run+0xc2/0x34e [ 402.824757] prog_array_map_poke_run+0xc2/0x34e [ 402.824765] bpf_fd_array_map_update_elem+0x124/0x1a0 [...] The elements concerned are walked as follows: for (i = 0; i < elem->aux->size_poke_tab; i++) { poke = &elem->aux->poke_tab[i]; [...] The access to size_poke_tab is a 4 byte read, verified by checking offsets in the KASAN dump: [ 402.825004] The buggy address belongs to the object at ffff8881905a7800 which belongs to the cache kmalloc-1k of size 1024 [ 402.825008] The buggy address is located 320 bytes inside of 1024-byte region [ffff8881905a7800, ffff8881905a7c00) The pahole output of bpf_prog_aux: struct bpf_prog_aux { [...] /* --- cacheline 5 boundary (320 bytes) --- */ u32 size_poke_tab; /* 320 4 */ [...] In general, subprograms do not necessarily manage their own data structures. For example, BTF func_info and linfo are just pointers to the main program structure. This allows reference counting and cleanup to be done on the latter which simplifies their management a bit. The aux->poke_tab struct, however, did not follow this logic. The initial proposed fix for this use-after-free bug further embedded poke data tracking into the subprogram with proper reference counting. However, Daniel and Alexei questioned why we were treating these objects special; I agree, its unnecessary. The fix here removes the per subprogram poke table allocation and map tracking and instead simply points the aux->poke_tab pointer at the main programs poke table. This way, map tracking is simplified to the main program and we do not need to manage them per subprogram. This also means, bpf_prog_free_deferred(), which unwinds the program reference counting and kfrees objects, needs to ensure that we don't try to double free the poke_tab when free'ing the subprog structures. This is easily solved by NULL'ing the poke_tab pointer. The second detail is to ensure that per subprogram JIT logic only does fixups on poke_tab[] entries it owns. To do this, we add a pointer in the poke structure to point at the subprogram value so JITs can easily check while walking the poke_tab structure if the current entry belongs to the current program. The aux pointer is stable and therefore suitable for such comparison. On the jit_subprogs() error path, we omit cleaning up the poke->aux field because these are only ever referenced from the JIT side, but on error we will never make it to the JIT, so its fine to leave them dangling. Removing these pointers would complicate the error path for no reason. However, we do need to untrack all poke descriptors from the main program as otherwise they could race with the freeing of JIT memory from the subprograms. Lastly, a748c6975dea3 ("bpf: propagate poke des ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mcb: fix error handling in mcb_alloc_bus() There are two bugs: 1) If ida_simple_get() fails then this code calls put_device(carrier) but we haven't yet called get_device(carrier) and probably that leads to a use after free. 2) After device_initialize() then we need to use put_device() to release the bus. This will free the internal resources tied to the device and call mcb_free_bus() which will free the rest.

In the Linux kernel, the following vulnerability has been resolved: igb: Fix use-after-free error during reset Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring. Failure to do so can cause invalid memory accesses. If igb_poll() runs while the controller is reset this can lead to the driver try to free a skb that was already freed. (The crash is harder to reproduce with the igb driver, but the same potential problem exists as the code is identical to igc)

An unauthorized access to the execution of the setuid file with capabilities flaw in the Linux kernel OverlayFS subsystem was found in the way user copying a capable file from a nosuid mount into another mount. A local user could use this flaw to escalate their privileges on the system.

In the Linux kernel, the following vulnerability has been resolved: net: marvell: prestera: fix double free issue on err path fix error path handling in prestera_bridge_port_join() that cases prestera driver to crash (see below). Trace: Internal error: Oops: 96000044 [#1] SMP Modules linked in: prestera_pci prestera uio_pdrv_genirq CPU: 1 PID: 881 Comm: ip Not tainted 5.15.0 #1 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : prestera_bridge_destroy+0x2c/0xb0 [prestera] lr : prestera_bridge_port_join+0x2cc/0x350 [prestera] sp : ffff800011a1b0f0 ... x2 : ffff000109ca6c80 x1 : dead000000000100 x0 : dead000000000122 Call trace: prestera_bridge_destroy+0x2c/0xb0 [prestera] prestera_bridge_port_join+0x2cc/0x350 [prestera] prestera_netdev_port_event.constprop.0+0x3c4/0x450 [prestera] prestera_netdev_event_handler+0xf4/0x110 [prestera] raw_notifier_call_chain+0x54/0x80 call_netdevice_notifiers_info+0x54/0xa0 __netdev_upper_dev_link+0x19c/0x380

IBM DB2 High Performance Unload load for LUW 6.1, 6.1.0.1, 6.1.0.1 IF1, 6.1.0.2, 6.1.0.2 IF1, and 6.1.0.1 IF2 db2hpum_debug is a setuid root binary which trusts the PATH environment variable. A low privileged user can execute arbitrary commands as root by altering the PATH variable to point to a user controlled location. When a crash is induced the trojan gdb command is executed. IBM X-Force ID: 163488.

In the Linux kernel, the following vulnerability has been resolved: media: davinci: vpif: fix use-after-free on driver unbind The driver allocates and registers two platform device structures during probe, but the devices were never deregistered on driver unbind. This results in a use-after-free on driver unbind as the device structures were allocated using devres and would be freed by driver core when remove() returns. Fix this by adding the missing deregistration calls to the remove() callback and failing probe on registration errors. Note that the platform device structures must be freed using a proper release callback to avoid leaking associated resources like device names.

In the Linux kernel, the following vulnerability has been resolved: net: dpaa2-eth: fix use-after-free in dpaa2_eth_remove Access to netdev after free_netdev() will cause use-after-free bug. Move debug log before free_netdev() call to avoid it.

A random memory access flaw was found in the Linux kernel's GPU i915 kernel driver functionality in the way a user may run malicious code on the GPU. This flaw allows a local user to crash the system or escalate their privileges on the system.

IBM DB2 High Performance Unload load for LUW 6.1, 6.1.0.1, 6.1.0.1 IF1, 6.1.0.2, 6.1.0.2 IF1, and 6.1.0.1 IF2 db2hpum and db2hpum_debug binaries are setuid root and have built-in options that allow an low privileged user the ability to load arbitrary db2 libraries from a privileged context. This results in arbitrary code being executed with root authority. IBM X-Force ID: 163489.

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_skbmod: Skip non-Ethernet packets Currently tcf_skbmod_act() assumes that packets use Ethernet as their L2 protocol, which is not always the case. As an example, for CAN devices: $ ip link add dev vcan0 type vcan $ ip link set up vcan0 $ tc qdisc add dev vcan0 root handle 1: htb $ tc filter add dev vcan0 parent 1: protocol ip prio 10 \ matchall action skbmod swap mac Doing the above silently corrupts all the packets. Do not perform skbmod actions for non-Ethernet packets.

In the Linux kernel, the following vulnerability has been resolved: net: usb: fix possible use-after-free in smsc75xx_bind The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind") fails to clean up the work scheduled in smsc75xx_reset-> smsc75xx_set_multicast, which leads to use-after-free if the work is scheduled to start after the deallocation. In addition, this patch also removes a dangling pointer - dev->data[0]. This patch calls cancel_work_sync to cancel the scheduled work and set the dangling pointer to NULL.

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix use-after-free in CCMP/GCMP RX When PN checking is done in mac80211, for fragmentation we need to copy the PN to the RX struct so we can later use it to do a comparison, since commit bf30ca922a0c ("mac80211: check defrag PN against current frame"). Unfortunately, in that commit I used the 'hdr' variable without it being necessarily valid, so use-after-free could occur if it was necessary to reallocate (parts of) the frame. Fix this by reloading the variable after the code that results in the reallocations, if any. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=214401.

In the Linux kernel, the following vulnerability has been resolved: can: sja1000: fix use after free in ems_pcmcia_add_card() If the last channel is not available then "dev" is freed. Fortunately, we can just use "pdev->irq" instead. Also we should check if at least one channel was set up.

In the Linux kernel, the following vulnerability has been resolved: Revert "Revert "block, bfq: honor already-setup queue merges"" A crash [1] happened to be triggered in conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq: honor already-setup queue merges""). Yet, the reverted commit was not the one introducing the bug. In fact, it actually triggered a UAF introduced by a different commit, and now fixed by commit d29bd41428cf ("block, bfq: reset last_bfqq_created on group change"). So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") out. This commit restores it. [1] https://bugzilla.kernel.org/show_bug.cgi?id=214503

A vulnerability in the ClearPass OnGuard Linux agent could allow malicious users on a Linux instance to elevate their user privileges to those of a higher role. A successful exploit allows malicious users to execute arbitrary code with root level privileges on the Linux instance.

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select() In resp_mode_select() sanity check the block descriptor len to avoid UAF. BUG: KASAN: use-after-free in resp_mode_select+0xa4c/0xb40 drivers/scsi/scsi_debug.c:2509 Read of size 1 at addr ffff888026670f50 by task scsicmd/15032 CPU: 1 PID: 15032 Comm: scsicmd Not tainted 5.15.0-01d0625 #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Call Trace: <TASK> dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:107 print_address_description.constprop.9+0x28/0x160 mm/kasan/report.c:257 kasan_report.cold.14+0x7d/0x117 mm/kasan/report.c:443 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 resp_mode_select+0xa4c/0xb40 drivers/scsi/scsi_debug.c:2509 schedule_resp+0x4af/0x1a10 drivers/scsi/scsi_debug.c:5483 scsi_debug_queuecommand+0x8c9/0x1e70 drivers/scsi/scsi_debug.c:7537 scsi_queue_rq+0x16b4/0x2d10 drivers/scsi/scsi_lib.c:1521 blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1640 __blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325 blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358 __blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1762 __blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1839 blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891 blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474 blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:63 sg_common_write.isra.18+0xeb3/0x2000 drivers/scsi/sg.c:837 sg_new_write.isra.19+0x570/0x8c0 drivers/scsi/sg.c:775 sg_ioctl_common+0x14d6/0x2710 drivers/scsi/sg.c:941 sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1166 __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:52 do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:50 entry_SYSCALL_64_after_hwframe+0x44/0xae arch/x86/entry/entry_64.S:113

In the Linux kernel, the following vulnerability has been resolved: net: bridge: fix vlan tunnel dst refcnt when egressing The egress tunnel code uses dst_clone() and directly sets the result which is wrong because the entry might have 0 refcnt or be already deleted, causing number of problems. It also triggers the WARN_ON() in dst_hold()[1] when a refcnt couldn't be taken. Fix it by using dst_hold_safe() and checking if a reference was actually taken before setting the dst. [1] dmesg WARN_ON log and following refcnt errors WARNING: CPU: 5 PID: 38 at include/net/dst.h:230 br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge] Modules linked in: 8021q garp mrp bridge stp llc bonding ipv6 virtio_net CPU: 5 PID: 38 Comm: ksoftirqd/5 Kdump: loaded Tainted: G W 5.13.0-rc3+ #360 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 RIP: 0010:br_handle_egress_vlan_tunnel+0x10b/0x134 [bridge] Code: e8 85 bc 01 e1 45 84 f6 74 90 45 31 f6 85 db 48 c7 c7 a0 02 19 a0 41 0f 94 c6 31 c9 31 d2 44 89 f6 e8 64 bc 01 e1 85 db 75 02 <0f> 0b 31 c9 31 d2 44 89 f6 48 c7 c7 70 02 19 a0 e8 4b bc 01 e1 49 RSP: 0018:ffff8881003d39e8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffffa01902a0 RBP: ffff8881040c6700 R08: 0000000000000000 R09: 0000000000000001 R10: 2ce93d0054fe0d00 R11: 54fe0d00000e0000 R12: ffff888109515000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000401 FS: 0000000000000000(0000) GS:ffff88822bf40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f42ba70f030 CR3: 0000000109926000 CR4: 00000000000006e0 Call Trace: br_handle_vlan+0xbc/0xca [bridge] __br_forward+0x23/0x164 [bridge] deliver_clone+0x41/0x48 [bridge] br_handle_frame_finish+0x36f/0x3aa [bridge] ? skb_dst+0x2e/0x38 [bridge] ? br_handle_ingress_vlan_tunnel+0x3e/0x1c8 [bridge] ? br_handle_frame_finish+0x3aa/0x3aa [bridge] br_handle_frame+0x2c3/0x377 [bridge] ? __skb_pull+0x33/0x51 ? vlan_do_receive+0x4f/0x36a ? br_handle_frame_finish+0x3aa/0x3aa [bridge] __netif_receive_skb_core+0x539/0x7c6 ? __list_del_entry_valid+0x16e/0x1c2 __netif_receive_skb_list_core+0x6d/0xd6 netif_receive_skb_list_internal+0x1d9/0x1fa gro_normal_list+0x22/0x3e dev_gro_receive+0x55b/0x600 ? detach_buf_split+0x58/0x140 napi_gro_receive+0x94/0x12e virtnet_poll+0x15d/0x315 [virtio_net] __napi_poll+0x2c/0x1c9 net_rx_action+0xe6/0x1fb __do_softirq+0x115/0x2d8 run_ksoftirqd+0x18/0x20 smpboot_thread_fn+0x183/0x19c ? smpboot_unregister_percpu_thread+0x66/0x66 kthread+0x10a/0x10f ? kthread_mod_delayed_work+0xb6/0xb6 ret_from_fork+0x22/0x30 ---[ end trace 49f61b07f775fd2b ]--- dst_release: dst:00000000c02d677a refcnt:-1 dst_release underflow

IBM DB2 High Performance Unload load for LUW 6.1 and 6.5 is vulnerable to a buffer overflow, caused by improper bounds checking which could allow a local attacker to execute arbitrary code on the system with root privileges. IBM X-Force ID: 165481.

In the Linux kernel, the following vulnerability has been resolved: devlink: fix possible use-after-free and memory leaks in devlink_init() The pernet operations structure for the subsystem must be registered before registering the generic netlink family. Make an unregister in case of unsuccessful registration.

In the Linux kernel, the following vulnerability has been resolved: vduse: fix memory corruption in vduse_dev_ioctl() The "config.offset" comes from the user. There needs to a check to prevent it being out of bounds. The "config.offset" and "dev->config_size" variables are both type u32. So if the offset if out of bounds then the "dev->config_size - config.offset" subtraction results in a very high u32 value. The out of bounds offset can result in memory corruption.

In the Linux kernel, the following vulnerability has been resolved: pid: take a reference when initializing `cad_pid` During boot, kernel_init_freeable() initializes `cad_pid` to the init task's struct pid. Later on, we may change `cad_pid` via a sysctl, and when this happens proc_do_cad_pid() will increment the refcount on the new pid via get_pid(), and will decrement the refcount on the old pid via put_pid(). As we never called get_pid() when we initialized `cad_pid`, we decrement a reference we never incremented, can therefore free the init task's struct pid early. As there can be dangling references to the struct pid, we can later encounter a use-after-free (e.g. when delivering signals). This was spotted when fuzzing v5.13-rc3 with Syzkaller, but seems to have been around since the conversion of `cad_pid` to struct pid in commit 9ec52099e4b8 ("[PATCH] replace cad_pid by a struct pid") from the pre-KASAN stone age of v2.6.19. Fix this by getting a reference to the init task's struct pid when we assign it to `cad_pid`. Full KASAN splat below. ================================================================== BUG: KASAN: use-after-free in ns_of_pid include/linux/pid.h:153 [inline] BUG: KASAN: use-after-free in task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509 Read of size 4 at addr ffff23794dda0004 by task syz-executor.0/273 CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1 Hardware name: linux,dummy-virt (DT) Call trace: ns_of_pid include/linux/pid.h:153 [inline] task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509 do_notify_parent+0x308/0xe60 kernel/signal.c:1950 exit_notify kernel/exit.c:682 [inline] do_exit+0x2334/0x2bd0 kernel/exit.c:845 do_group_exit+0x108/0x2c8 kernel/exit.c:922 get_signal+0x4e4/0x2a88 kernel/signal.c:2781 do_signal arch/arm64/kernel/signal.c:882 [inline] do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936 work_pending+0xc/0x2dc Allocated by task 0: slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516 slab_alloc_node mm/slub.c:2907 [inline] slab_alloc mm/slub.c:2915 [inline] kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920 alloc_pid+0xdc/0xc00 kernel/pid.c:180 copy_process+0x2794/0x5e18 kernel/fork.c:2129 kernel_clone+0x194/0x13c8 kernel/fork.c:2500 kernel_thread+0xd4/0x110 kernel/fork.c:2552 rest_init+0x44/0x4a0 init/main.c:687 arch_call_rest_init+0x1c/0x28 start_kernel+0x520/0x554 init/main.c:1064 0x0 Freed by task 270: slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kmem_cache_free+0x224/0x8e0 mm/slub.c:3177 put_pid.part.4+0xe0/0x1a8 kernel/pid.c:114 put_pid+0x30/0x48 kernel/pid.c:109 proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401 proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591 proc_sys_write+0x34/0x48 fs/proc/proc_sysctl.c:617 call_write_iter include/linux/fs.h:1977 [inline] new_sync_write+0x3ac/0x510 fs/read_write.c:518 vfs_write fs/read_write.c:605 [inline] vfs_write+0x9c4/0x1018 fs/read_write.c:585 ksys_write+0x124/0x240 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __arm64_sys_write+0x78/0xb0 fs/read_write.c:667 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall arch/arm64/kernel/syscall.c:49 [inline] el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129 do_el0_svc+0xf8/0x150 arch/arm64/kernel/syscall.c:168 el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416 el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432 el0_sync+0x154/0x180 arch/arm64/kernel/entry.S:701 The buggy address belongs to the object at ffff23794dda0000 which belongs to the cache pid of size 224 The buggy address is located 4 bytes inside of 224-byte region [ff ---truncated---

In drivers/char/virtio_console.c in the Linux kernel before 5.13.4, data corruption or loss can be triggered by an untrusted device that supplies a buf->len value exceeding the buffer size. NOTE: the vendor indicates that the cited data corruption is not a vulnerability in any existing use case; the length validation was added solely for robustness in the face of anomalous host OS behavior

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix use after free on rmmod plat_dev->dev->platform_data is released by platform_device_unregister(), use of pclk and hclk is a use-after-free. Since device unregister won't need a clk device we adjust the function call sequence to fix this issue. [ 31.261225] BUG: KASAN: use-after-free in macb_remove+0x77/0xc6 [macb_pci] [ 31.275563] Freed by task 306: [ 30.276782] platform_device_release+0x25/0x80

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 is vulnerable to a buffer overflow, which could allow an authenticated local attacker to execute arbitrary code on the system as root. IBM X-Force ID: 158519.

In the Linux kernel, the following vulnerability has been resolved: tomoyo: fix UAF write bug in tomoyo_write_control() Since tomoyo_write_control() updates head->write_buf when write() of long lines is requested, we need to fetch head->write_buf after head->io_sem is held. Otherwise, concurrent write() requests can cause use-after-free-write and double-free problems.

In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix double free of the ha->vp_map pointer Coverity scan reported potential risk of double free of the pointer ha->vp_map. ha->vp_map was freed in qla2x00_mem_alloc(), and again freed in function qla2x00_mem_free(ha). Assign NULL to vp_map and kfree take care of NULL.

In the Linux kernel, the following vulnerability has been resolved: clk: mediatek: mt7622-apmixedsys: Fix an error handling path in clk_mt8135_apmixed_probe() 'clk_data' is allocated with mtk_devm_alloc_clk_data(). So calling mtk_free_clk_data() explicitly in the remove function would lead to a double-free. Remove the redundant call.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: Correct the PDO counting in pd_set Off-by-one errors happen because nr_snk_pdo and nr_src_pdo are incorrectly added one. The index of the loop is equal to the number of PDOs to be updated when leaving the loop and it doesn't need to be added one. When doing the power negotiation, TCPM relies on the "nr_snk_pdo" as the size of the local sink PDO array to match the Source capabilities of the partner port. If the off-by-one overflow occurs, a wrong RDO might be sent and unexpected power transfer might happen such as over voltage or over current (than expected). "nr_src_pdo" is used to set the Rp level when the port is in Source role. It is also the array size of the local Source capabilities when filling up the buffer which will be sent as the Source PDOs (such as in Power Negotiation). If the off-by-one overflow occurs, a wrong Rp level might be set and wrong Source PDOs will be sent to the partner port. This could potentially cause over current or port resets.

In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: fix memory double free when handle zero packet 829 if (request->complete) { 830 spin_unlock(&priv_dev->lock); 831 usb_gadget_giveback_request(&priv_ep->endpoint, 832 request); 833 spin_lock(&priv_dev->lock); 834 } 835 836 if (request->buf == priv_dev->zlp_buf) 837 cdns3_gadget_ep_free_request(&priv_ep->endpoint, request); Driver append an additional zero packet request when queue a packet, which length mod max packet size is 0. When transfer complete, run to line 831, usb_gadget_giveback_request() will free this requestion. 836 condition is true, so cdns3_gadget_ep_free_request() free this request again. Log: [ 1920.140696][ T150] BUG: KFENCE: use-after-free read in cdns3_gadget_giveback+0x134/0x2c0 [cdns3] [ 1920.140696][ T150] [ 1920.151837][ T150] Use-after-free read at 0x000000003d1cd10b (in kfence-#36): [ 1920.159082][ T150] cdns3_gadget_giveback+0x134/0x2c0 [cdns3] [ 1920.164988][ T150] cdns3_transfer_completed+0x438/0x5f8 [cdns3] Add check at line 829, skip call usb_gadget_giveback_request() if it is additional zero length packet request. Needn't call usb_gadget_giveback_request() because it is allocated in this driver.

In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encode_cap_msg() In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.