Quick Emulator (Qemu) built with the 'chardev' backend support is vulnerable to a use after free issue. It could occur while hotplug and unplugging the device in the guest. A guest user/process could use this flaw to crash a Qemu process on the host resulting in DoS.

popd in bash might allow local users to bypass the restricted shell and cause a use-after-free via a crafted address.

In drivers/media/dvb-core/dmxdev.c in the Linux kernel through 5.19.10, there is a use-after-free caused by refcount races, affecting dvb_demux_open and dvb_dmxdev_release.

A flaw was found in the Linux kernel’s networking code. A use-after-free was found in the way the sch_sfb enqueue function used the socket buffer (SKB) cb field after the same SKB had been enqueued (and freed) into a child qdisc. This flaw allows a local, unprivileged user to crash the system, causing a denial of service.

drivers/block/floppy.c in the Linux kernel before 5.17.6 is vulnerable to a denial of service, because of a concurrency use-after-free flaw after deallocating raw_cmd in the raw_cmd_ioctl function.

Use-after-free vulnerability in the vmxnet3_io_bar0_write function in hw/net/vmxnet3.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU instance crash) by leveraging failure to check if the device is active.

Use-after-free vulnerability in hw/pci/pcie.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (QEMU instance crash) via hotplug and hotunplug operations of Virtio block devices.

QEMU 5.0.0 has a use-after-free in hw/usb/hcd-xhci.c because the usb_packet_map return value is not checked.

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach This is the candidate patch of CVE-2023-47233 : https://nvd.nist.gov/vuln/detail/CVE-2023-47233 In brcm80211 driver,it starts with the following invoking chain to start init a timeout worker: ->brcmf_usb_probe ->brcmf_usb_probe_cb ->brcmf_attach ->brcmf_bus_started ->brcmf_cfg80211_attach ->wl_init_priv ->brcmf_init_escan ->INIT_WORK(&cfg->escan_timeout_work, brcmf_cfg80211_escan_timeout_worker); If we disconnect the USB by hotplug, it will call brcmf_usb_disconnect to make cleanup. The invoking chain is : brcmf_usb_disconnect ->brcmf_usb_disconnect_cb ->brcmf_detach ->brcmf_cfg80211_detach ->kfree(cfg); While the timeout woker may still be running. This will cause a use-after-free bug on cfg in brcmf_cfg80211_escan_timeout_worker. Fix it by deleting the timer and canceling the worker in brcmf_cfg80211_detach. [arend.vanspriel@broadcom.com: keep timer delete as is and cancel work just before free]

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix possible use-after-free and null-ptr-deref The pernet operations structure for the subsystem must be registered before registering the generic netlink family.

There are use-after-free vulnerabilities caused by timer handler in net/rose/rose_timer.c of linux that allow attackers to crash linux kernel without any privileges.

A NULL pointer dereference flaw was found in the Linux kernel’s X.25 set of standardized network protocols functionality in the way a user terminates their session using a simulated Ethernet card and continued usage of this connection. This flaw allows a local user to crash the system.

A use-after-free flaw was found in the Linux kernel’s Amateur Radio AX.25 protocol functionality in the way a user connects with the protocol. This flaw allows a local user to crash the system.

A use-after-free vulnerability was found in the Linux kernel in drivers/net/hamradio. This flaw allows a local attacker with a user privilege to cause a denial of service (DOS) when the mkiss or sixpack device is detached and reclaim resources early.

A heap use-after-free flaw was found in coders/bmp.c in ImageMagick.

The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __cil_verify_classpermission and __cil_pre_verify_helper).

The CIL compiler in SELinux 3.2 has a use-after-free in cil_reset_classpermission (called from cil_reset_classperms_set and cil_reset_classperms_list).

The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __verify_map_perm_classperms and hashtab_map).

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid panic in f2fs_evict_inode As syzbot [1] reported as below: R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe17473450 R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520 </TASK> ---[ end trace 0000000000000000 ]--- ================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 Read of size 8 at addr ffff88812d962278 by task syz-executor/564 CPU: 1 PID: 564 Comm: syz-executor Tainted: G W 6.1.129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x158 lib/dump_stack.c:106 print_address_description+0x71/0x210 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:427 kasan_report+0x122/0x150 mm/kasan/report.c:531 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 __list_del_entry include/linux/list.h:134 [inline] list_del_init include/linux/list.h:206 [inline] f2fs_inode_synced+0xf7/0x2e0 fs/f2fs/super.c:1531 f2fs_update_inode+0x74/0x1c40 fs/f2fs/inode.c:585 f2fs_update_inode_page+0x137/0x170 fs/f2fs/inode.c:703 f2fs_write_inode+0x4ec/0x770 fs/f2fs/inode.c:731 write_inode fs/fs-writeback.c:1460 [inline] __writeback_single_inode+0x4a0/0xab0 fs/fs-writeback.c:1677 writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733 sync_inode_metadata+0xb6/0x110 fs/fs-writeback.c:2789 f2fs_sync_inode_meta+0x16d/0x2a0 fs/f2fs/checkpoint.c:1159 block_operations fs/f2fs/checkpoint.c:1269 [inline] f2fs_write_checkpoint+0xca3/0x2100 fs/f2fs/checkpoint.c:1658 kill_f2fs_super+0x231/0x390 fs/f2fs/super.c:4668 deactivate_locked_super+0x98/0x100 fs/super.c:332 deactivate_super+0xaf/0xe0 fs/super.c:363 cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1186 __cleanup_mnt+0x19/0x20 fs/namespace.c:1193 task_work_run+0x1c6/0x230 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x9fb/0x2410 kernel/exit.c:871 do_group_exit+0x210/0x2d0 kernel/exit.c:1021 __do_sys_exit_group kernel/exit.c:1032 [inline] __se_sys_exit_group kernel/exit.c:1030 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1030 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f28b1b8e169 Code: Unable to access opcode bytes at 0x7f28b1b8e13f. RSP: 002b:00007ffe174710a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f28b1c10879 RCX: 00007f28b1b8e169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000002 R08: 00007ffe1746ee47 R09: 00007ffe17472360 R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffe17472360 R13: 00007f28b1c10854 R14: 000000000000dae5 R15: 00007ffe17474520 </TASK> Allocated by task 569: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4f/0x2c0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc_lru+0x104/0x220 mm/slub.c:3429 alloc_inode_sb include/linux/fs.h:3245 [inline] f2fs_alloc_inode+0x2d/0x340 fs/f2fs/super.c:1419 alloc_inode fs/inode.c:261 [inline] iget_locked+0x186/0x880 fs/inode.c:1373 f2fs_iget+0x55/0x4c60 fs/f2fs/inode.c:483 f2fs_lookup+0x366/0xab0 fs/f2fs/namei.c:487 __lookup_slow+0x2a3/0x3d0 fs/namei.c:1690 lookup_slow+0x57/0x70 fs/namei.c:1707 walk_component+0x2e6/0x410 fs/namei ---truncated---

Use-after-Free vulnerability in cflow 1.6 in the void call(char *name, int line) function at src/parser.c, which could cause a denial of service via the pointer variable caller->callee.

A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

An issue was discovered in OpenEXR before 2.5.2. Invalid input could cause a use-after-free in DeepScanLineInputFile::DeepScanLineInputFile() in IlmImf/ImfDeepScanLineInputFile.cpp.

QEMU 4.2.0 has a use-after-free in hw/net/e1000e_core.c because a guest OS user can trigger an e1000e packet with the data's address set to the e1000e's MMIO address.

A possible use-after-free and double-free in c-ares lib version 1.16.0 if ares_destroy() is called prior to ares_getaddrinfo() completing. This flaw possibly allows an attacker to crash the service that uses c-ares lib. The highest threat from this vulnerability is to this service availability.

A use-after-free vulnerability was found in the cxgb4 driver in the Linux kernel. The bug occurs when the cxgb4 device is detaching due to a possible rearming of the flower_stats_timer from the work queue. This flaw allows a local user to crash the system, causing a denial of service condition.

A use-after-free vulnerability was found in the cyttsp4_core driver in the Linux kernel. This issue occurs in the device cleanup routine due to a possible rearming of the watchdog_timer from the workqueue. This could allow a local user to crash the system, causing a denial of service.

A use-after-free vulnerability was found in the siano smsusb module in the Linux kernel. The bug occurs during device initialization when the siano device is plugged in. This flaw allows a local user to crash the system, causing a denial of service condition.

Vixie Cron before the 3.0pl1-133 Debian package allows local users to cause a denial of service (use-after-free and daemon crash) because of a force_rescan_user error.

In the Linux kernel before 5.1.6, there is a use-after-free in cpia2_exit() in drivers/media/usb/cpia2/cpia2_v4l.c that will cause denial of service, aka CID-dea37a972655.

In the Linux kernel 5.3.11, mounting a crafted btrfs image twice can cause an rwsem_down_write_slowpath use-after-free because (in rwsem_can_spin_on_owner in kernel/locking/rwsem.c) rwsem_owner_flags returns an already freed pointer,

In the Linux kernel, the following vulnerability has been resolved: ACPICA: Refuse to evaluate a method if arguments are missing As reported in [1], a platform firmware update that increased the number of method parameters and forgot to update a least one of its callers, caused ACPICA to crash due to use-after-free. Since this a result of a clear AML issue that arguably cannot be fixed up by the interpreter (it cannot produce missing data out of thin air), address it by making ACPICA refuse to evaluate a method if the caller attempts to pass fewer arguments than expected to it.

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: prime: fix ttm_bo_delayed_delete oops Fix an oops in ttm_bo_delayed_delete which results from dererencing a dangling pointer: Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b7b: 0000 [#1] PREEMPT SMP CPU: 4 UID: 0 PID: 1082 Comm: kworker/u65:2 Not tainted 6.14.0-rc4-00267-g505460b44513-dirty #216 Hardware name: LENOVO 82N6/LNVNB161216, BIOS GKCN65WW 01/16/2024 Workqueue: ttm ttm_bo_delayed_delete [ttm] RIP: 0010:dma_resv_iter_first_unlocked+0x55/0x290 Code: 31 f6 48 c7 c7 00 2b fa aa e8 97 bd 52 ff e8 a2 c1 53 00 5a 85 c0 74 48 e9 88 01 00 00 4c 89 63 20 4d 85 e4 0f 84 30 01 00 00 <41> 8b 44 24 10 c6 43 2c 01 48 89 df 89 43 28 e8 97 fd ff ff 4c 8b RSP: 0018:ffffbf9383473d60 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffffbf9383473d88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffbf9383473d78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 6b6b6b6b6b6b6b6b R13: ffffa003bbf78580 R14: ffffa003a6728040 R15: 00000000000383cc FS: 0000000000000000(0000) GS:ffffa00991c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000758348024dd0 CR3: 000000012c259000 CR4: 0000000000f50ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x26 ? die_addr+0x3d/0x70 ? exc_general_protection+0x159/0x460 ? asm_exc_general_protection+0x27/0x30 ? dma_resv_iter_first_unlocked+0x55/0x290 dma_resv_wait_timeout+0x56/0x100 ttm_bo_delayed_delete+0x69/0xb0 [ttm] process_one_work+0x217/0x5c0 worker_thread+0x1c8/0x3d0 ? apply_wqattrs_cleanup.part.0+0xc0/0xc0 kthread+0x10b/0x240 ? kthreads_online_cpu+0x140/0x140 ret_from_fork+0x40/0x70 ? kthreads_online_cpu+0x140/0x140 ret_from_fork_asm+0x11/0x20 </TASK> The cause of this is: - drm_prime_gem_destroy calls dma_buf_put(dma_buf) which releases the reference to the shared dma_buf. The reference count is 0, so the dma_buf is destroyed, which in turn decrements the corresponding amdgpu_bo reference count to 0, and the amdgpu_bo is destroyed - calling drm_gem_object_release then dma_resv_fini (which destroys the reservation object), then finally freeing the amdgpu_bo. - nouveau_bo obj->bo.base.resv is now a dangling pointer to the memory formerly allocated to the amdgpu_bo. - nouveau_gem_object_del calls ttm_bo_put(&nvbo->bo) which calls ttm_bo_release, which schedules ttm_bo_delayed_delete. - ttm_bo_delayed_delete runs and dereferences the dangling resv pointer, resulting in a general protection fault. Fix this by moving the drm_prime_gem_destroy call from nouveau_gem_object_del to nouveau_bo_del_ttm. This ensures that it will be run after ttm_bo_delayed_delete.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_sync_inode_meta() syzbot reported an UAF issue as below: [1] [2] [1] https://syzkaller.appspot.com/text?tag=CrashReport&x=16594c60580000 ================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 Read of size 8 at addr ffff888100567dc8 by task kworker/u4:0/8 CPU: 1 PID: 8 Comm: kworker/u4:0 Tainted: G W 6.1.129-syzkaller-00017-g642656a36791 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 __list_del_entry include/linux/list.h:134 [inline] list_del_init include/linux/list.h:206 [inline] f2fs_inode_synced+0x100/0x2e0 fs/f2fs/super.c:1553 f2fs_update_inode+0x72/0x1c40 fs/f2fs/inode.c:588 f2fs_update_inode_page+0x135/0x170 fs/f2fs/inode.c:706 f2fs_write_inode+0x416/0x790 fs/f2fs/inode.c:734 write_inode fs/fs-writeback.c:1460 [inline] __writeback_single_inode+0x4cf/0xb80 fs/fs-writeback.c:1677 writeback_sb_inodes+0xb32/0x1910 fs/fs-writeback.c:1903 __writeback_inodes_wb+0x118/0x3f0 fs/fs-writeback.c:1974 wb_writeback+0x3da/0xa00 fs/fs-writeback.c:2081 wb_check_background_flush fs/fs-writeback.c:2151 [inline] wb_do_writeback fs/fs-writeback.c:2239 [inline] wb_workfn+0xbba/0x1030 fs/fs-writeback.c:2266 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Allocated by task 298: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc_lru+0x102/0x270 mm/slub.c:3454 alloc_inode_sb include/linux/fs.h:3255 [inline] f2fs_alloc_inode+0x2d/0x350 fs/f2fs/super.c:1437 alloc_inode fs/inode.c:261 [inline] iget_locked+0x18c/0x7e0 fs/inode.c:1373 f2fs_iget+0x55/0x4ca0 fs/f2fs/inode.c:486 f2fs_lookup+0x3c1/0xb50 fs/f2fs/namei.c:484 __lookup_slow+0x2b9/0x3e0 fs/namei.c:1689 lookup_slow+0x5a/0x80 fs/namei.c:1706 walk_component+0x2e7/0x410 fs/namei.c:1997 lookup_last fs/namei.c:2454 [inline] path_lookupat+0x16d/0x450 fs/namei.c:2478 filename_lookup+0x251/0x600 fs/namei.c:2507 vfs_statx+0x107/0x4b0 fs/stat.c:229 vfs_fstatat fs/stat.c:267 [inline] vfs_lstat include/linux/fs.h:3434 [inline] __do_sys_newlstat fs/stat.c:423 [inline] __se_sys_newlstat+0xda/0x7c0 fs/stat.c:417 __x64_sys_newlstat+0x5b/0x70 fs/stat.c:417 x64_sys_call+0x52/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:7 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 0: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x ---truncated---

A use-after-free flaw was found in fs/ext4/namei.c:dx_insert_block() in the Linux kernel’s filesystem sub-component. This flaw allows a local attacker with a user privilege to cause a denial of service.

A use-after-free flaw was found in the MegaRAID emulator of QEMU. This issue occurs while processing SCSI I/O requests in the case of an error mptsas_free_request() that does not dequeue the request object 'req' from a pending requests queue. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. Versions between 2.10.0 and 5.2.0 are potentially affected.

iproute2 before 5.1.0 has a use-after-free in get_netnsid_from_name in ip/ipnetns.c. NOTE: security relevance may be limited to certain uses of setuid that, although not a default, are sometimes a configuration option offered to end users. Even when setuid is used, other factors (such as C library configuration) may block exploitability.

Sander Bos discovered Apport's lock file was in a world-writable directory which allowed all users to prevent crash handling.

Improper conditions check in the voltage modulation interface for some Intel(R) Xeon(R) Scalable Processors may allow a privileged user to potentially enable denial of service via local access.

Insufficient access control in subsystem for Intel (R) processor graphics in 6th, 7th, 8th and 9th Generation Intel(R) Core(TM) Processor Families; Intel(R) Pentium(R) Processor J, N, Silver and Gold Series; Intel(R) Celeron(R) Processor J, N, G3900 and G4900 Series; Intel(R) Atom(R) Processor A and E3900 Series; Intel(R) Xeon(R) Processor E3-1500 v5 and v6 and E-2100 Processor Families may allow an authenticated user to potentially enable denial of service via local access.

An unhandled exception in check_ignored() in apport/report.py can be exploited by a local attacker to cause a denial of service. If the mtime attribute is a string value in apport-ignore.xml, it will trigger an unhandled exception, resulting in a crash. Fixed in 2.20.1-0ubuntu2.24, 2.20.9-0ubuntu7.16, 2.20.11-0ubuntu27.6.

A vulnerability was found in the avahi library. This flaw allows an unprivileged user to make a dbus call, causing the avahi daemon to crash.

The unimac_mdio_probe function in drivers/net/phy/mdio-bcm-unimac.c in the Linux kernel through 4.15.8 does not validate certain resource availability, which allows local users to cause a denial of service (NULL pointer dereference).

Quick Emulator (aka QEMU), when built with the Cirrus CLGD 54xx VGA Emulator support, allows local guest OS privileged users to cause a denial of service (out-of-bounds access and QEMU process crash) by leveraging incorrect region calculation when updating VGA display.

The libevt_record_values_read_event() function in libevt_record_values.c in libevt before 2018-03-17 does not properly check for out-of-bounds values of user SID data size, strings size, or data size. NOTE: the vendor has disputed this as described in libyal/libevt issue 5 on GitHub

A deadlock flaw was found in the Linux kernel’s BPF subsystem. This flaw allows a local user to potentially crash the system.