The inet_csk_clone_lock function in net/ipv4/inet_connection_sock.c in the Linux kernel through 4.10.15 allows attackers to cause a denial of service (double free) or possibly have unspecified other impact by leveraging use of the accept system call.

In the Linux kernel, the following vulnerability has been resolved: mm/slab_common: fix possible double free of kmem_cache When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt'

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix a use-after-free when hitting errors inside btrfs_submit_chunk() [BUG] There is an internal report that KASAN is reporting use-after-free, with the following backtrace: BUG: KASAN: slab-use-after-free in btrfs_check_read_bio+0xa68/0xb70 [btrfs] Read of size 4 at addr ffff8881117cec28 by task kworker/u16:2/45 CPU: 1 UID: 0 PID: 45 Comm: kworker/u16:2 Not tainted 6.11.0-rc2-next-20240805-default+ #76 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] Call Trace: dump_stack_lvl+0x61/0x80 print_address_description.constprop.0+0x5e/0x2f0 print_report+0x118/0x216 kasan_report+0x11d/0x1f0 btrfs_check_read_bio+0xa68/0xb70 [btrfs] process_one_work+0xce0/0x12a0 worker_thread+0x717/0x1250 kthread+0x2e3/0x3c0 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x11/0x20 Allocated by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x7d/0x80 kmem_cache_alloc_noprof+0x16e/0x3e0 mempool_alloc_noprof+0x12e/0x310 bio_alloc_bioset+0x3f0/0x7a0 btrfs_bio_alloc+0x2e/0x50 [btrfs] submit_extent_page+0x4d1/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x50 __kasan_slab_free+0x4b/0x60 kmem_cache_free+0x214/0x5d0 bio_free+0xed/0x180 end_bbio_data_read+0x1cc/0x580 [btrfs] btrfs_submit_chunk+0x98d/0x1880 [btrfs] btrfs_submit_bio+0x33/0x70 [btrfs] submit_one_bio+0xd4/0x130 [btrfs] submit_extent_page+0x3ea/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [CAUSE] Although I cannot reproduce the error, the report itself is good enough to pin down the cause. The call trace is the regular endio workqueue context, but the free-by-task trace is showing that during btrfs_submit_chunk() we already hit a critical error, and is calling btrfs_bio_end_io() to error out. And the original endio function called bio_put() to free the whole bio. This means a double freeing thus causing use-after-free, e.g.: 1. Enter btrfs_submit_bio() with a read bio The read bio length is 128K, crossing two 64K stripes. 2. The first run of btrfs_submit_chunk() 2.1 Call btrfs_map_block(), which returns 64K 2.2 Call btrfs_split_bio() Now there are two bios, one referring to the first 64K, the other referring to the second 64K. 2.3 The first half is submitted. 3. The second run of btrfs_submit_chunk() 3.1 Call btrfs_map_block(), which by somehow failed Now we call btrfs_bio_end_io() to handle the error 3.2 btrfs_bio_end_io() calls the original endio function Which is end_bbio_data_read(), and it calls bio_put() for the original bio. Now the original bio is freed. 4. The submitted first 64K bio finished Now we call into btrfs_check_read_bio() and tries to advance the bio iter. But since the original bio (thus its iter) is already freed, we trigger the above use-after free. And even if the memory is not poisoned/corrupted, we will later call the original endio function, causing a double freeing. [FIX] Instead of calling btrfs_bio_end_io(), call btrfs_orig_bbio_end_io(), which has the extra check on split bios and do the pr ---truncated---

In the Linux kernel, the following vulnerability has been resolved: scsi: aacraid: Fix double-free on probe failure aac_probe_one() calls hardware-specific init functions through the aac_driver_ident::init pointer, all of which eventually call down to aac_init_adapter(). If aac_init_adapter() fails after allocating memory for aac_dev::queues, it frees the memory but does not clear that member. After the hardware-specific init function returns an error, aac_probe_one() goes down an error path that frees the memory pointed to by aac_dev::queues, resulting.in a double-free.

In the Linux kernel, the following vulnerability has been resolved: ata: libata-core: Fix double free on error If e.g. the ata_port_alloc() call in ata_host_alloc() fails, we will jump to the err_out label, which will call devres_release_group(). devres_release_group() will trigger a call to ata_host_release(). ata_host_release() calls kfree(host), so executing the kfree(host) in ata_host_alloc() will lead to a double free: kernel BUG at mm/slub.c:553! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 11 PID: 599 Comm: (udev-worker) Not tainted 6.10.0-rc5 #47 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:kfree+0x2cf/0x2f0 Code: 5d 41 5e 41 5f 5d e9 80 d6 ff ff 4d 89 f1 41 b8 01 00 00 00 48 89 d9 48 89 da RSP: 0018:ffffc90000f377f0 EFLAGS: 00010246 RAX: ffff888112b1f2c0 RBX: ffff888112b1f2c0 RCX: ffff888112b1f320 RDX: 000000000000400b RSI: ffffffffc02c9de5 RDI: ffff888112b1f2c0 RBP: ffffc90000f37830 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000f37610 R11: 617461203a736b6e R12: ffffea00044ac780 R13: ffff888100046400 R14: ffffffffc02c9de5 R15: 0000000000000006 FS: 00007f2f1cabe980(0000) GS:ffff88813b380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f1c3acf75 CR3: 0000000111724000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? die+0x2e/0x50 ? do_trap+0xca/0x110 ? do_error_trap+0x6a/0x90 ? kfree+0x2cf/0x2f0 ? exc_invalid_op+0x50/0x70 ? kfree+0x2cf/0x2f0 ? asm_exc_invalid_op+0x1a/0x20 ? ata_host_alloc+0xf5/0x120 [libata] ? ata_host_alloc+0xf5/0x120 [libata] ? kfree+0x2cf/0x2f0 ata_host_alloc+0xf5/0x120 [libata] ata_host_alloc_pinfo+0x14/0xa0 [libata] ahci_init_one+0x6c9/0xd20 [ahci] Ensure that we will not call kfree(host) twice, by performing the kfree() only if the devres_open_group() call failed.

In the Linux kernel, the following vulnerability has been resolved: nvme: avoid double free special payload If a discard request needs to be retried, and that retry may fail before a new special payload is added, a double free will result. Clear the RQF_SPECIAL_LOAD when the request is cleaned.

The dccp_rcv_state_process function in net/dccp/input.c in the Linux kernel through 4.9.11 mishandles DCCP_PKT_REQUEST packet data structures in the LISTEN state, which allows local users to obtain root privileges or cause a denial of service (double free) via an application that makes an IPV6_RECVPKTINFO setsockopt system call.

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: lantiq_etop: fix double free in detach The number of the currently released descriptor is never incremented which results in the same skb being released multiple times.

In the Linux kernel, the following vulnerability has been resolved: HID: elan: Fix potential double free in elan_input_configured 'input' is a managed resource allocated with devm_input_allocate_device(), so there is no need to call input_free_device() explicitly or there will be a double free. According to the doc of devm_input_allocate_device(): * Managed input devices do not need to be explicitly unregistered or * freed as it will be done automatically when owner device unbinds from * its driver (or binding fails).

In the Linux kernel, the following vulnerability has been resolved: cifs: fix double free race when mount fails in cifs_get_root() When cifs_get_root() fails during cifs_smb3_do_mount() we call deactivate_locked_super() which eventually will call delayed_free() which will free the context. In this situation we should not proceed to enter the out: section in cifs_smb3_do_mount() and free the same resources a second time. [Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0 [Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G OE 5.17.0-rc3+ #4 [Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019 [Thu Feb 10 12:59:06 2022] Call Trace: [Thu Feb 10 12:59:06 2022] <IRQ> [Thu Feb 10 12:59:06 2022] dump_stack_lvl+0x5d/0x78 [Thu Feb 10 12:59:06 2022] print_address_description.constprop.0+0x24/0x150 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] kasan_report.cold+0x7d/0x117 [Thu Feb 10 12:59:06 2022] ? rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] __asan_load8+0x86/0xa0 [Thu Feb 10 12:59:06 2022] rcu_cblist_dequeue+0x32/0x60 [Thu Feb 10 12:59:06 2022] rcu_core+0x547/0xca0 [Thu Feb 10 12:59:06 2022] ? call_rcu+0x3c0/0x3c0 [Thu Feb 10 12:59:06 2022] ? __this_cpu_preempt_check+0x13/0x20 [Thu Feb 10 12:59:06 2022] ? lock_is_held_type+0xea/0x140 [Thu Feb 10 12:59:06 2022] rcu_core_si+0xe/0x10 [Thu Feb 10 12:59:06 2022] __do_softirq+0x1d4/0x67b [Thu Feb 10 12:59:06 2022] __irq_exit_rcu+0x100/0x150 [Thu Feb 10 12:59:06 2022] irq_exit_rcu+0xe/0x30 [Thu Feb 10 12:59:06 2022] sysvec_hyperv_stimer0+0x9d/0xc0 ... [Thu Feb 10 12:59:07 2022] Freed by task 58179: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] kasan_set_track+0x25/0x30 [Thu Feb 10 12:59:07 2022] kasan_set_free_info+0x24/0x40 [Thu Feb 10 12:59:07 2022] ____kasan_slab_free+0x137/0x170 [Thu Feb 10 12:59:07 2022] __kasan_slab_free+0x12/0x20 [Thu Feb 10 12:59:07 2022] slab_free_freelist_hook+0xb3/0x1d0 [Thu Feb 10 12:59:07 2022] kfree+0xcd/0x520 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0x149/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae [Thu Feb 10 12:59:07 2022] Last potentially related work creation: [Thu Feb 10 12:59:07 2022] kasan_save_stack+0x26/0x50 [Thu Feb 10 12:59:07 2022] __kasan_record_aux_stack+0xb6/0xc0 [Thu Feb 10 12:59:07 2022] kasan_record_aux_stack_noalloc+0xb/0x10 [Thu Feb 10 12:59:07 2022] call_rcu+0x76/0x3c0 [Thu Feb 10 12:59:07 2022] cifs_umount+0xce/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] cifs_kill_sb+0xc8/0xe0 [cifs] [Thu Feb 10 12:59:07 2022] deactivate_locked_super+0x5d/0xd0 [Thu Feb 10 12:59:07 2022] cifs_smb3_do_mount+0xab9/0xbe0 [cifs] [Thu Feb 10 12:59:07 2022] smb3_get_tree+0x1a0/0x2e0 [cifs] [Thu Feb 10 12:59:07 2022] vfs_get_tree+0x52/0x140 [Thu Feb 10 12:59:07 2022] path_mount+0x635/0x10c0 [Thu Feb 10 12:59:07 2022] __x64_sys_mount+0x1bf/0x210 [Thu Feb 10 12:59:07 2022] do_syscall_64+0x5c/0xc0 [Thu Feb 10 12:59:07 2022] entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: cifs: fix potential double free during failed mount RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2088799

In the Linux kernel, the following vulnerability has been resolved: misc: ocxl: fix possible double free in ocxl_file_register_afu info_release() will be called in device_unregister() when info->dev's reference count is 0. So there is no need to call ocxl_afu_put() and kfree() again. Fix this by adding free_minor() and return to err_unregister error path.

In the Linux kernel, the following vulnerability has been resolved: md: fix double free of io_acct_set bioset Now io_acct_set is alloc and free in personality. Remove the codes that free io_acct_set in md_free and md_stop.

In the Linux kernel, the following vulnerability has been resolved: remoteproc: mtk_scp: Fix a potential double free 'scp->rproc' is allocated using devm_rproc_alloc(), so there is no need to free it explicitly in the remove function.

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix potential double free in create_var_ref() In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref().

A double-free flaw was found in the Linux kernel’s TUN/TAP device driver functionality in how a user registers the device when the register_netdevice function fails (NETDEV_REGISTER notifier). This flaw allows a local user to crash or potentially escalate their privileges on the system.

In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Fix init stage error handling to avoid double free of same QP and UAF In the unlikely event that workqueue allocation fails and returns NULL in mlx5_mkey_cache_init(), delete the call to mlx5r_umr_resource_cleanup() (which frees the QP) in mlx5_ib_stage_post_ib_reg_umr_init(). This will avoid attempted double free of the same QP when __mlx5_ib_add() does its cleanup. Resolves a splat: Syzkaller reported a UAF in ib_destroy_qp_user workqueue: Failed to create a rescuer kthread for wq "mkey_cache": -EINTR infiniband mlx5_0: mlx5_mkey_cache_init:981:(pid 1642): failed to create work queue infiniband mlx5_0: mlx5_ib_stage_post_ib_reg_umr_init:4075:(pid 1642): mr cache init failed -12 ================================================================== BUG: KASAN: slab-use-after-free in ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073) Read of size 8 at addr ffff88810da310a8 by task repro_upstream/1642 Call Trace: <TASK> kasan_report (mm/kasan/report.c:590) ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2073) mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4178) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ... </TASK> Allocated by task 1642: __kmalloc (./include/linux/kasan.h:198 mm/slab_common.c:1026 mm/slab_common.c:1039) create_qp (./include/linux/slab.h:603 ./include/linux/slab.h:720 ./include/rdma/ib_verbs.h:2795 drivers/infiniband/core/verbs.c:1209) ib_create_qp_kernel (drivers/infiniband/core/verbs.c:1347) mlx5r_umr_resource_init (drivers/infiniband/hw/mlx5/umr.c:164) mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4070) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ... Freed by task 1642: __kmem_cache_free (mm/slub.c:1826 mm/slub.c:3809 mm/slub.c:3822) ib_destroy_qp_user (drivers/infiniband/core/verbs.c:2112) mlx5r_umr_resource_cleanup (drivers/infiniband/hw/mlx5/umr.c:198) mlx5_ib_stage_post_ib_reg_umr_init (drivers/infiniband/hw/mlx5/main.c:4076 drivers/infiniband/hw/mlx5/main.c:4065) __mlx5_ib_add (drivers/infiniband/hw/mlx5/main.c:4168) mlx5r_probe (drivers/infiniband/hw/mlx5/main.c:4402) ...

An issue was discovered in the Linux kernel before 4.14.11. A double free may be caused by the function allocate_trace_buffer in the file kernel/trace/trace.c.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: fix double-free issue in tcpm_port_unregister_pd() When unregister pd capabilitie in tcpm, KASAN will capture below double -free issue. The root cause is the same capabilitiy will be kfreed twice, the first time is kfreed by pd_capabilities_release() and the second time is explicitly kfreed by tcpm_port_unregister_pd(). [ 3.988059] BUG: KASAN: double-free in tcpm_port_unregister_pd+0x1a4/0x3dc [ 3.995001] Free of addr ffff0008164d3000 by task kworker/u16:0/10 [ 4.001206] [ 4.002712] CPU: 2 PID: 10 Comm: kworker/u16:0 Not tainted 6.8.0-rc5-next-20240220-05616-g52728c567a55 #53 [ 4.012402] Hardware name: Freescale i.MX8QXP MEK (DT) [ 4.017569] Workqueue: events_unbound deferred_probe_work_func [ 4.023456] Call trace: [ 4.025920] dump_backtrace+0x94/0xec [ 4.029629] show_stack+0x18/0x24 [ 4.032974] dump_stack_lvl+0x78/0x90 [ 4.036675] print_report+0xfc/0x5c0 [ 4.040289] kasan_report_invalid_free+0xa0/0xc0 [ 4.044937] __kasan_slab_free+0x124/0x154 [ 4.049072] kfree+0xb4/0x1e8 [ 4.052069] tcpm_port_unregister_pd+0x1a4/0x3dc [ 4.056725] tcpm_register_port+0x1dd0/0x2558 [ 4.061121] tcpci_register_port+0x420/0x71c [ 4.065430] tcpci_probe+0x118/0x2e0 To fix the issue, this will remove kree() from tcpm_port_unregister_pd().

In the Linux kernel, the following vulnerability has been resolved: stm class: Fix a double free in stm_register_device() The put_device(&stm->dev) call will trigger stm_device_release() which frees "stm" so the vfree(stm) on the next line is a double free.

In the Linux kernel, the following vulnerability has been resolved: mac80211: fix potential double free on mesh join While commit 6a01afcf8468 ("mac80211: mesh: Free ie data when leaving mesh") fixed a memory leak on mesh leave / teardown it introduced a potential memory corruption caused by a double free when rejoining the mesh: ieee80211_leave_mesh() -> kfree(sdata->u.mesh.ie); ... ieee80211_join_mesh() -> copy_mesh_setup() -> old_ie = ifmsh->ie; -> kfree(old_ie); This double free / kernel panics can be reproduced by using wpa_supplicant with an encrypted mesh (if set up without encryption via "iw" then ifmsh->ie is always NULL, which avoids this issue). And then calling: $ iw dev mesh0 mesh leave $ iw dev mesh0 mesh join my-mesh Note that typically these commands are not used / working when using wpa_supplicant. And it seems that wpa_supplicant or wpa_cli are going through a NETDEV_DOWN/NETDEV_UP cycle between a mesh leave and mesh join where the NETDEV_UP resets the mesh.ie to NULL via a memcpy of default_mesh_setup in cfg80211_netdev_notifier_call, which then avoids the memory corruption, too. The issue was first observed in an application which was not using wpa_supplicant but "Senf" instead, which implements its own calls to nl80211. Fixing the issue by removing the kfree()'ing of the mesh IE in the mesh join function and leaving it solely up to the mesh leave to free the mesh IE.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix double free in si_parse_power_table() In function si_parse_power_table(), array adev->pm.dpm.ps and its member is allocated. If the allocation of each member fails, the array itself is freed and returned with an error code. However, the array is later freed again in si_dpm_fini() function which is called when the function returns an error. This leads to potential double free of the array adev->pm.dpm.ps, as well as leak of its array members, since the members are not freed in the allocation function and the array is not nulled when freed. In addition adev->pm.dpm.num_ps, which keeps track of the allocated array member, is not updated until the member allocation is successfully finished, this could also lead to either use after free, or uninitialized variable access in si_dpm_fini(). Fix this by postponing the free of the array until si_dpm_fini() and increment adev->pm.dpm.num_ps everytime the array member is allocated.

In the Linux kernel, the following vulnerability has been resolved: sched/core: Fix use-after-free bug in dup_user_cpus_ptr() Since commit 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems"), the setting and clearing of user_cpus_ptr are done under pi_lock for arm64 architecture. However, dup_user_cpus_ptr() accesses user_cpus_ptr without any lock protection. Since sched_setaffinity() can be invoked from another process, the process being modified may be undergoing fork() at the same time. When racing with the clearing of user_cpus_ptr in __set_cpus_allowed_ptr_locked(), it can lead to user-after-free and possibly double-free in arm64 kernel. Commit 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") fixes this problem as user_cpus_ptr, once set, will never be cleared in a task's lifetime. However, this bug was re-introduced in commit 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in do_set_cpus_allowed(). This time, it will affect all arches. Fix this bug by always clearing the user_cpus_ptr of the newly cloned/forked task before the copying process starts and check the user_cpus_ptr state of the source task under pi_lock. Note to stable, this patch won't be applicable to stable releases. Just copy the new dup_user_cpus_ptr() function over.

Race condition in the netlink_dump function in net/netlink/af_netlink.c in the Linux kernel before 4.6.3 allows local users to cause a denial of service (double free) or possibly have unspecified other impact via a crafted application that makes sendmsg system calls, leading to a free operation associated with a new dump that started earlier than anticipated.

The blkcg_init_queue function in block/blk-cgroup.c in the Linux kernel before 4.11 allows local users to cause a denial of service (double free) or possibly have unspecified other impact by triggering a creation failure.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: mediatek: Fix double free of skb in coredump hci_devcd_append() would free the skb on error so the caller don't have to free it again otherwise it would cause the double free of skb. Reported-by : Dan Carpenter <dan.carpenter@linaro.org>

A double-free flaw was found in the Linux kernel’s NTFS3 subsystem in how a user triggers remount and umount simultaneously. This flaw allows a local user to crash or potentially escalate their privileges on the system.

In the Linux kernel, the following vulnerability has been resolved: media: atomisp: Fix use after free in atomisp_alloc_css_stat_bufs() The "s3a_buf" is freed along with all the other items on the "asd->s3a_stats" list. It leads to a double free and a use after free.

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: 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: 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: usb: misc: ljca: Fix double free in error handling path When auxiliary_device_add() returns error and then calls auxiliary_device_uninit(), callback function ljca_auxdev_release calls kfree(auxdev->dev.platform_data) to free the parameter data of the function ljca_new_client_device. The callers of ljca_new_client_device shouldn't call kfree() again in the error handling path to free the platform data. Fix this by cleaning up the redundant kfree() in all callers and adding kfree() the passed in platform_data on errors which happen before auxiliary_device_init() succeeds .

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: fix double-free bug The storage for the TLV PC register data wasn't done like all the other storage in the drv->fw area, which is cleared at the end of deallocation. Therefore, the freeing must also be done differently, explicitly NULL'ing it out after the free, since otherwise there's a nasty double-free bug here if a file fails to load after this has been parsed, and we get another free later (e.g. because no other file exists.) Fix that by adding the missing NULL assignment.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.

ems_usb_start_xmit in drivers/net/can/usb/ems_usb.c in the Linux kernel through 5.17.1 has a double free.

drivers/infiniband/ulp/rtrs/rtrs-clt.c in the Linux kernel before 5.16.12 has a double free related to rtrs_clt_dev_release.

It was discovered that the cls_route filter implementation in the Linux kernel would not remove an old filter from the hashtable before freeing it if its handle had the value 0.

io_uring use work_flags to determine which identity need to grab from the calling process to make sure it is consistent with the calling process when executing IORING_OP. Some operations are missing some types, which can lead to incorrect reference counts which can then lead to a double free. We recommend upgrading the kernel past commit df3f3bb5059d20ef094d6b2f0256c4bf4127a859

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: Don't free command immediately Don't prematurely free the command. Wait for the status completion of the sense status. It can be freed then. Otherwise we will double-free the command.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix handling of plane refcount [Why] The mechanism to backup and restore plane states doesn't maintain refcount, which can cause issues if the refcount of the plane changes in between backup and restore operations, such as memory leaks if the refcount was supposed to go down, or double frees / invalid memory accesses if the refcount was supposed to go up. [How] Cache and re-apply current refcount when restoring plane states.

In the Linux kernel, the following vulnerability has been resolved: media: uvcvideo: Fix double free in error path If the uvc_status_init() function fails to allocate the int_urb, it will free the dev->status pointer but doesn't reset the pointer to NULL. This results in the kfree() call in uvc_status_cleanup() trying to double-free the memory. Fix it by resetting the dev->status pointer to NULL after freeing it. Reviewed by: Ricardo Ribalda <ribalda@chromium.org>

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Fix double free in OPTEE transport Channels can be shared between protocols, avoid freeing the same channel descriptors twice when unloading the stack.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix double brelse() the buffer of the extents path In ext4_ext_try_to_merge_up(), set path[1].p_bh to NULL after it has been released, otherwise it may be released twice. An example of what triggers this is as follows: split2 map split1 |--------|-------|--------| ext4_ext_map_blocks ext4_ext_handle_unwritten_extents ext4_split_convert_extents // path->p_depth == 0 ext4_split_extent // 1. do split1 ext4_split_extent_at |ext4_ext_insert_extent | ext4_ext_create_new_leaf | ext4_ext_grow_indepth | le16_add_cpu(&neh->eh_depth, 1) | ext4_find_extent | // return -ENOMEM |// get error and try zeroout |path = ext4_find_extent | path->p_depth = 1 |ext4_ext_try_to_merge | ext4_ext_try_to_merge_up | path->p_depth = 0 | brelse(path[1].p_bh) ---> not set to NULL here |// zeroout success // 2. update path ext4_find_extent // 3. do split2 ext4_split_extent_at ext4_ext_insert_extent ext4_ext_create_new_leaf ext4_ext_grow_indepth le16_add_cpu(&neh->eh_depth, 1) ext4_find_extent path[0].p_bh = NULL; path->p_depth = 1 read_extent_tree_block ---> return err // path[1].p_bh is still the old value ext4_free_ext_path ext4_ext_drop_refs // path->p_depth == 1 brelse(path[1].p_bh) ---> brelse a buffer twice Finally got the following WARRNING when removing the buffer from lru: ============================================ VFS: brelse: Trying to free free buffer WARNING: CPU: 2 PID: 72 at fs/buffer.c:1241 __brelse+0x58/0x90 CPU: 2 PID: 72 Comm: kworker/u19:1 Not tainted 6.9.0-dirty #716 RIP: 0010:__brelse+0x58/0x90 Call Trace: <TASK> __find_get_block+0x6e7/0x810 bdev_getblk+0x2b/0x480 __ext4_get_inode_loc+0x48a/0x1240 ext4_get_inode_loc+0xb2/0x150 ext4_reserve_inode_write+0xb7/0x230 __ext4_mark_inode_dirty+0x144/0x6a0 ext4_ext_insert_extent+0x9c8/0x3230 ext4_ext_map_blocks+0xf45/0x2dc0 ext4_map_blocks+0x724/0x1700 ext4_do_writepages+0x12d6/0x2a70 [...] ============================================

In the Linux kernel, the following vulnerability has been resolved: net: vertexcom: mse102x: Fix possible double free of TX skb The scope of the TX skb is wider than just mse102x_tx_frame_spi(), so in case the TX skb room needs to be expanded, we should free the the temporary skb instead of the original skb. Otherwise the original TX skb pointer would be freed again in mse102x_tx_work(), which leads to crashes: Internal error: Oops: 0000000096000004 [#2] PREEMPT SMP CPU: 0 PID: 712 Comm: kworker/0:1 Tainted: G D 6.6.23 Hardware name: chargebyte Charge SOM DC-ONE (DT) Workqueue: events mse102x_tx_work [mse102x] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_release_data+0xb8/0x1d8 lr : skb_release_data+0x1ac/0x1d8 sp : ffff8000819a3cc0 x29: ffff8000819a3cc0 x28: ffff0000046daa60 x27: ffff0000057f2dc0 x26: ffff000005386c00 x25: 0000000000000002 x24: 00000000ffffffff x23: 0000000000000000 x22: 0000000000000001 x21: ffff0000057f2e50 x20: 0000000000000006 x19: 0000000000000000 x18: ffff00003fdacfcc x17: e69ad452d0c49def x16: 84a005feff870102 x15: 0000000000000000 x14: 000000000000024a x13: 0000000000000002 x12: 0000000000000000 x11: 0000000000000400 x10: 0000000000000930 x9 : ffff00003fd913e8 x8 : fffffc00001bc008 x7 : 0000000000000000 x6 : 0000000000000008 x5 : ffff00003fd91340 x4 : 0000000000000000 x3 : 0000000000000009 x2 : 00000000fffffffe x1 : 0000000000000000 x0 : 0000000000000000 Call trace: skb_release_data+0xb8/0x1d8 kfree_skb_reason+0x48/0xb0 mse102x_tx_work+0x164/0x35c [mse102x] process_one_work+0x138/0x260 worker_thread+0x32c/0x438 kthread+0x118/0x11c ret_from_fork+0x10/0x20 Code: aa1303e0 97fffab6 72001c1f 54000141 (f9400660)

In the Linux kernel, the following vulnerability has been resolved: nvmet-auth: assign dh_key to NULL after kfree_sensitive ctrl->dh_key might be used across multiple calls to nvmet_setup_dhgroup() for the same controller. So it's better to nullify it after release on error path in order to avoid double free later in nvmet_destroy_auth(). Found by Linux Verification Center (linuxtesting.org) with Svace.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: fix a potential double-free in fs_any_create_groups When kcalloc() for ft->g succeeds but kvzalloc() for in fails, fs_any_create_groups() will free ft->g. However, its caller fs_any_create_table() will free ft->g again through calling mlx5e_destroy_flow_table(), which will lead to a double-free. Fix this by setting ft->g to NULL in fs_any_create_groups().

In the Linux kernel, the following vulnerability has been resolved: net: atlantic: eliminate double free in error handling logic Driver has a logic leak in ring data allocation/free, where aq_ring_free could be called multiple times on same ring, if system is under stress and got memory allocation error. Ring pointer was used as an indicator of failure, but this is not correct since only ring data is allocated/deallocated. Ring itself is an array member. Changing ring allocation functions to return error code directly. This simplifies error handling and eliminates aq_ring_free on higher layer.

In the Linux kernel, the following vulnerability has been resolved: drm/i915: Fix potential bit_17 double-free A userspace with multiple threads racing I915_GEM_SET_TILING to set the tiling to I915_TILING_NONE could trigger a double free of the bit_17 bitmask. (Or conversely leak memory on the transition to tiled.) Move allocation/free'ing of the bitmask within the section protected by the obj lock. [tursulin: Correct fixes tag and added cc stable.] (cherry picked from commit 10e0cbaaf1104f449d695c80bcacf930dcd3c42e)

In the Linux kernel, the following vulnerability has been resolved: of: Fix double free in of_parse_phandle_with_args_map In of_parse_phandle_with_args_map() the inner loop that iterates through the map entries calls of_node_put(new) to free the reference acquired by the previous iteration of the inner loop. This assumes that the value of "new" is NULL on the first iteration of the inner loop. Make sure that this is true in all iterations of the outer loop by setting "new" to NULL after its value is assigned to "cur". Extend the unittest to detect the double free and add an additional test case that actually triggers this path.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix a double-free in si_dpm_init When the allocation of adev->pm.dpm.dyn_state.vddc_dependency_on_dispclk.entries fails, amdgpu_free_extended_power_table is called to free some fields of adev. However, when the control flow returns to si_dpm_sw_init, it goes to label dpm_failed and calls si_dpm_fini, which calls amdgpu_free_extended_power_table again and free those fields again. Thus a double-free is triggered.