Total
650 CVE
| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2024-26691 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-12-20 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix circular locking dependency The rule inside kvm enforces that the vcpu->mutex is taken *inside* kvm->lock. The rule is violated by the pkvm_create_hyp_vm() which acquires the kvm->lock while already holding the vcpu->mutex lock from kvm_vcpu_ioctl(). Avoid the circular locking dependency altogether by protecting the hyp vm handle with the config_lock, much like we already do for other forms of VM-scoped data. | ||||
| CVE-2025-37940 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-19 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: ftrace: Add cond_resched() to ftrace_graph_set_hash() When the kernel contains a large number of functions that can be traced, the loop in ftrace_graph_set_hash() may take a lot of time to execute. This may trigger the softlockup watchdog. Add cond_resched() within the loop to allow the kernel to remain responsive even when processing a large number of functions. This matches the cond_resched() that is used in other locations of the code that iterates over all functions that can be traced. | ||||
| CVE-2025-38058 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: __legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock ... or we risk stealing final mntput from sync umount - raising mnt_count after umount(2) has verified that victim is not busy, but before it has set MNT_SYNC_UMOUNT; in that case __legitimize_mnt() doesn't see that it's safe to quietly undo mnt_count increment and leaves dropping the reference to caller, where it'll be a full-blown mntput(). Check under mount_lock is needed; leaving the current one done before taking that makes no sense - it's nowhere near common enough to bother with. | ||||
| CVE-2021-47632 | 1 Linux | 1 Linux Kernel | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38 ("powerpc/mm: Implement set_memory() routines") included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_page_attr(). To do the operation atomically, we can't use pte modification helpers anymore. Because all platforms have different combination of bits, it is not easy to use those bits directly. But all have the _PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare two sets to know which bits are set or cleared. For instance, by comparing _PAGE_KERNEL_ROX and _PAGE_KERNEL_RO you know which bit gets cleared and which bit get set when changing exec permission. | ||||
| CVE-2021-47622 | 1 Linux | 1 Linux Kernel | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: Fix a deadlock in the error handler The following deadlock has been observed on a test setup: - All tags allocated - The SCSI error handler calls ufshcd_eh_host_reset_handler() - ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler() - ufshcd_err_handler() locks up as follows: Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt Call trace: __switch_to+0x298/0x5d8 __schedule+0x6cc/0xa94 schedule+0x12c/0x298 blk_mq_get_tag+0x210/0x480 __blk_mq_alloc_request+0x1c8/0x284 blk_get_request+0x74/0x134 ufshcd_exec_dev_cmd+0x68/0x640 ufshcd_verify_dev_init+0x68/0x35c ufshcd_probe_hba+0x12c/0x1cb8 ufshcd_host_reset_and_restore+0x88/0x254 ufshcd_reset_and_restore+0xd0/0x354 ufshcd_err_handler+0x408/0xc58 process_one_work+0x24c/0x66c worker_thread+0x3e8/0xa4c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved request. | ||||
| CVE-2021-47582 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: USB: core: Make do_proc_control() and do_proc_bulk() killable The USBDEVFS_CONTROL and USBDEVFS_BULK ioctls invoke usb_start_wait_urb(), which contains an uninterruptible wait with a user-specified timeout value. If timeout value is very large and the device being accessed does not respond in a reasonable amount of time, the kernel will complain about "Task X blocked for more than N seconds", as found in testing by syzbot: INFO: task syz-executor.0:8700 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23192 pid: 8700 ppid: 8455 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0xc07/0x11f0 kernel/sched/core.c:5938 schedule+0x14b/0x210 kernel/sched/core.c:6017 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857 do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157 usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63 do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236 proc_bulk drivers/usb/core/devio.c:1273 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline] usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713 ... To fix this problem, this patch replaces usbfs's calls to usb_control_msg() and usb_bulk_msg() with special-purpose code that does essentially the same thing (as recommended in the comment for usb_start_wait_urb()), except that it always uses a killable wait and it uses GFP_KERNEL rather than GFP_NOIO. | ||||
| CVE-2021-47468 | 2 Linux, Redhat | 6 Linux Kernel, Enterprise Linux, Rhel Aus and 3 more | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: isdn: mISDN: Fix sleeping function called from invalid context The driver can call card->isac.release() function from an atomic context. Fix this by calling this function after releasing the lock. The following log reveals it: [ 44.168226 ] BUG: sleeping function called from invalid context at kernel/workqueue.c:3018 [ 44.168941 ] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 5475, name: modprobe [ 44.169574 ] INFO: lockdep is turned off. [ 44.169899 ] irq event stamp: 0 [ 44.170160 ] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [ 44.170627 ] hardirqs last disabled at (0): [<ffffffff814209ed>] copy_process+0x132d/0x3e00 [ 44.171240 ] softirqs last enabled at (0): [<ffffffff81420a1a>] copy_process+0x135a/0x3e00 [ 44.171852 ] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 44.172318 ] Preemption disabled at: [ 44.172320 ] [<ffffffffa009b0a9>] nj_release+0x69/0x500 [netjet] [ 44.174441 ] Call Trace: [ 44.174630 ] dump_stack_lvl+0xa8/0xd1 [ 44.174912 ] dump_stack+0x15/0x17 [ 44.175166 ] ___might_sleep+0x3a2/0x510 [ 44.175459 ] ? nj_release+0x69/0x500 [netjet] [ 44.175791 ] __might_sleep+0x82/0xe0 [ 44.176063 ] ? start_flush_work+0x20/0x7b0 [ 44.176375 ] start_flush_work+0x33/0x7b0 [ 44.176672 ] ? trace_irq_enable_rcuidle+0x85/0x170 [ 44.177034 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177372 ] ? kasan_quarantine_put+0xaa/0x1f0 [ 44.177711 ] __flush_work+0x11a/0x1a0 [ 44.177991 ] ? flush_work+0x20/0x20 [ 44.178257 ] ? lock_release+0x13c/0x8f0 [ 44.178550 ] ? __kasan_check_write+0x14/0x20 [ 44.178872 ] ? do_raw_spin_lock+0x148/0x360 [ 44.179187 ] ? read_lock_is_recursive+0x20/0x20 [ 44.179530 ] ? __kasan_check_read+0x11/0x20 [ 44.179846 ] ? do_raw_spin_unlock+0x55/0x900 [ 44.180168 ] ? ____kasan_slab_free+0x116/0x140 [ 44.180505 ] ? _raw_spin_unlock_irqrestore+0x41/0x60 [ 44.180878 ] ? skb_queue_purge+0x1a3/0x1c0 [ 44.181189 ] ? kfree+0x13e/0x290 [ 44.181438 ] flush_work+0x17/0x20 [ 44.181695 ] mISDN_freedchannel+0xe8/0x100 [ 44.182006 ] isac_release+0x210/0x260 [mISDNipac] [ 44.182366 ] nj_release+0xf6/0x500 [netjet] [ 44.182685 ] nj_remove+0x48/0x70 [netjet] [ 44.182989 ] pci_device_remove+0xa9/0x250 | ||||
| CVE-2021-47408 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-12-18 | 4.7 Medium |
| In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: serialize hash resizes and cleanups Syzbot was able to trigger the following warning [1] No repro found by syzbot yet but I was able to trigger similar issue by having 2 scripts running in parallel, changing conntrack hash sizes, and: for j in `seq 1 1000` ; do unshare -n /bin/true >/dev/null ; done It would take more than 5 minutes for net_namespace structures to be cleaned up. This is because nf_ct_iterate_cleanup() has to restart everytime a resize happened. By adding a mutex, we can serialize hash resizes and cleanups and also make get_next_corpse() faster by skipping over empty buckets. Even without resizes in the picture, this patch considerably speeds up network namespace dismantles. [1] INFO: task syz-executor.0:8312 can't die for more than 144 seconds. task:syz-executor.0 state:R running task stack:25672 pid: 8312 ppid: 6573 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6408 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __local_bh_enable_ip+0x109/0x120 kernel/softirq.c:390 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2252 [inline] nf_ct_iterate_cleanup+0x15a/0x450 net/netfilter/nf_conntrack_core.c:2275 nf_conntrack_cleanup_net_list+0x14c/0x4f0 net/netfilter/nf_conntrack_core.c:2469 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 setup_net+0x639/0xa30 net/core/net_namespace.c:349 copy_net_ns+0x319/0x760 net/core/net_namespace.c:470 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3128 __do_sys_unshare kernel/fork.c:3202 [inline] __se_sys_unshare kernel/fork.c:3200 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3200 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f63da68e739 RSP: 002b:00007f63d7c05188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f63da792f80 RCX: 00007f63da68e739 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f63da6e8cc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f63da792f80 R13: 00007fff50b75d3f R14: 00007f63d7c05300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b980020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 2 locks held by kworker/u4:2/153: #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc9000140fdb0 ((kfence_timer).work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 1 lock held by systemd-udevd/2970: 1 lock held by in:imklog/6258: #0: ffff88807f970ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/1:6/8158: 1 lock held by syz-executor.0/8312: 2 locks held by kworker/u4:13/9320: 1 lock held by ---truncated--- | ||||
| CVE-2021-47359 | 1 Linux | 1 Linux Kernel | 2025-12-18 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: cifs: Fix soft lockup during fsstress Below traces are observed during fsstress and system got hung. [ 130.698396] watchdog: BUG: soft lockup - CPU#6 stuck for 26s! | ||||
| CVE-2021-47185 | 2 Linux, Redhat | 2 Linux Kernel, Enterprise Linux | 2025-12-18 | 4.4 Medium |
| In the Linux kernel, the following vulnerability has been resolved: tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc When running ltp testcase(ltp/testcases/kernel/pty/pty04.c) with arm64, there is a soft lockup, which look like this one: Workqueue: events_unbound flush_to_ldisc Call trace: dump_backtrace+0x0/0x1ec show_stack+0x24/0x30 dump_stack+0xd0/0x128 panic+0x15c/0x374 watchdog_timer_fn+0x2b8/0x304 __run_hrtimer+0x88/0x2c0 __hrtimer_run_queues+0xa4/0x120 hrtimer_interrupt+0xfc/0x270 arch_timer_handler_phys+0x40/0x50 handle_percpu_devid_irq+0x94/0x220 __handle_domain_irq+0x88/0xf0 gic_handle_irq+0x84/0xfc el1_irq+0xc8/0x180 slip_unesc+0x80/0x214 [slip] tty_ldisc_receive_buf+0x64/0x80 tty_port_default_receive_buf+0x50/0x90 flush_to_ldisc+0xbc/0x110 process_one_work+0x1d4/0x4b0 worker_thread+0x180/0x430 kthread+0x11c/0x120 In the testcase pty04, The first process call the write syscall to send data to the pty master. At the same time, the workqueue will do the flush_to_ldisc to pop data in a loop until there is no more data left. When the sender and workqueue running in different core, the sender sends data fastly in full time which will result in workqueue doing work in loop for a long time and occuring softlockup in flush_to_ldisc with kernel configured without preempt. So I add need_resched check and cond_resched in the flush_to_ldisc loop to avoid it. | ||||
| CVE-2025-48618 | 1 Google | 1 Android | 2025-12-17 | 6.6 Medium |
| In processLaunchBrowser of CommandParamsFactory.java, there is a possible browser interaction from the lockscreen due to improper locking. This could lead to physical escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. | ||||
| CVE-2025-37970 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo Prevent st_lsm6dsx_read_fifo from falling in an infinite loop in case pattern_len is equal to zero and the device FIFO is not empty. | ||||
| CVE-2025-37969 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_tagged_fifo Prevent st_lsm6dsx_read_tagged_fifo from falling in an infinite loop in case pattern_len is equal to zero and the device FIFO is not empty. | ||||
| CVE-2025-37968 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: iio: light: opt3001: fix deadlock due to concurrent flag access The threaded IRQ function in this driver is reading the flag twice: once to lock a mutex and once to unlock it. Even though the code setting the flag is designed to prevent it, there are subtle cases where the flag could be true at the mutex_lock stage and false at the mutex_unlock stage. This results in the mutex not being unlocked, resulting in a deadlock. Fix it by making the opt3001_irq() code generally more robust, reading the flag into a variable and using the variable value at both stages. | ||||
| CVE-2025-37967 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: displayport: Fix deadlock This patch introduces the ucsi_con_mutex_lock / ucsi_con_mutex_unlock functions to the UCSI driver. ucsi_con_mutex_lock ensures the connector mutex is only locked if a connection is established and the partner pointer is valid. This resolves a deadlock scenario where ucsi_displayport_remove_partner holds con->mutex waiting for dp_altmode_work to complete while dp_altmode_work attempts to acquire it. | ||||
| CVE-2025-37997 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: fix region locking in hash types Region locking introduced in v5.6-rc4 contained three macros to handle the region locks: ahash_bucket_start(), ahash_bucket_end() which gave back the start and end hash bucket values belonging to a given region lock and ahash_region() which should give back the region lock belonging to a given hash bucket. The latter was incorrect which can lead to a race condition between the garbage collector and adding new elements when a hash type of set is defined with timeouts. | ||||
| CVE-2023-3889 | 1 Arm | 1 Valhall Gpu Kernel Driver | 2025-12-16 | 7.8 High |
| A local non-privileged user can make improper GPU memory processing operations. If the operations are carefully prepared, then they could be used to gain access to already freed memory. | ||||
| CVE-2025-38335 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: Input: gpio-keys - fix a sleep while atomic with PREEMPT_RT When enabling PREEMPT_RT, the gpio_keys_irq_timer() callback runs in hard irq context, but the input_event() takes a spin_lock, which isn't allowed there as it is converted to a rt_spin_lock(). [ 4054.289999] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 4054.290028] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/0 ... [ 4054.290195] __might_resched+0x13c/0x1f4 [ 4054.290209] rt_spin_lock+0x54/0x11c [ 4054.290219] input_event+0x48/0x80 [ 4054.290230] gpio_keys_irq_timer+0x4c/0x78 [ 4054.290243] __hrtimer_run_queues+0x1a4/0x438 [ 4054.290257] hrtimer_interrupt+0xe4/0x240 [ 4054.290269] arch_timer_handler_phys+0x2c/0x44 [ 4054.290283] handle_percpu_devid_irq+0x8c/0x14c [ 4054.290297] handle_irq_desc+0x40/0x58 [ 4054.290307] generic_handle_domain_irq+0x1c/0x28 [ 4054.290316] gic_handle_irq+0x44/0xcc Considering the gpio_keys_irq_isr() can run in any context, e.g. it can be threaded, it seems there's no point in requesting the timer isr to run in hard irq context. Relax the hrtimer not to use the hard context. | ||||
| CVE-2025-38094 | 2 Debian, Linux | 2 Debian Linux, Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: net: cadence: macb: Fix a possible deadlock in macb_halt_tx. There is a situation where after THALT is set high, TGO stays high as well. Because jiffies are never updated, as we are in a context with interrupts disabled, we never exit that loop and have a deadlock. That deadlock was noticed on a sama5d4 device that stayed locked for days. Use retries instead of jiffies so that the timeout really works and we do not have a deadlock anymore. | ||||
| CVE-2025-21710 | 1 Linux | 1 Linux Kernel | 2025-12-16 | 5.5 Medium |
| In the Linux kernel, the following vulnerability has been resolved: tcp: correct handling of extreme memory squeeze Testing with iperf3 using the "pasta" protocol splicer has revealed a problem in the way tcp handles window advertising in extreme memory squeeze situations. Under memory pressure, a socket endpoint may temporarily advertise a zero-sized window, but this is not stored as part of the socket data. The reasoning behind this is that it is considered a temporary setting which shouldn't influence any further calculations. However, if we happen to stall at an unfortunate value of the current window size, the algorithm selecting a new value will consistently fail to advertise a non-zero window once we have freed up enough memory. This means that this side's notion of the current window size is different from the one last advertised to the peer, causing the latter to not send any data to resolve the sitution. The problem occurs on the iperf3 server side, and the socket in question is a completely regular socket with the default settings for the fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket. The following excerpt of a logging session, with own comments added, shows more in detail what is happening: // tcp_v4_rcv(->) // tcp_rcv_established(->) [5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ==== [5201<->39222]: tcp_data_queue(->) [5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0] [OFO queue: gap: 65480, len: 0] [5201<->39222]: tcp_data_queue(<-) [5201<->39222]: __tcp_transmit_skb(->) [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: tcp_select_window(->) [5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] returning 0 [5201<->39222]: tcp_select_window(<-) [5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160 [5201<->39222]: [__tcp_transmit_skb(<-) [5201<->39222]: tcp_rcv_established(<-) [5201<->39222]: tcp_v4_rcv(<-) // Receive queue is at 85 buffers and we are out of memory. // We drop the incoming buffer, although it is in sequence, and decide // to send an advertisement with a window of zero. // We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means // we unconditionally shrink the window. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368] [5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0] [5201<->39222]: NOT calling tcp_send_ack() [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: __tcp_cleanup_rbuf(<-) [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0] returning 6104 bytes [5201<->39222]: tcp_recvmsg_locked(<-) // After each read, the algorithm for calculating the new receive // window in __tcp_cleanup_rbuf() finds it is too small to advertise // or to update tp->rcv_wnd. // Meanwhile, the peer thinks the window is zero, and will not send // any more data to trigger an update from the interrupt mode side. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_n ---truncated--- | ||||