Sicherheitslücken in linux-azure · Seite 199

video: fbdev: i740fb: Check the argument of i740_calc_vclk()

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: i740fb: Check the argument of i740_calc_vclk() Since the user can control the arguments of the ioctl() from the user space, under special arguments that may result in a divide-by-zero bug. If the user provides an improper 'pixclock' value that makes the argumet of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a divide-by-zero bug in: drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX))); The following log can reveal it: divide error: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:i740_calc_vclk dri

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kprobes: don't call disarm_kprobe() for disabled kprobes

In the Linux kernel, the following vulnerability has been resolved: kprobes: don't call disarm_kprobe() for disabled kprobes The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can easily reproduce this issue. 1. Write 0 to /sys/kernel/debug/kprobes/enabled. # echo 0 > /sys/kernel/debug/kprobes/enabled 2. Run execsnoop. At this time, one kprobe is disabled. # /usr/share/bcc/tools/execsnoop & [1] 2460 PCOMM PID PPID RET ARGS # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffff

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xfrm: fix refcount leak in __xfrm_policy_check()

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix refcount leak in __xfrm_policy_check() The issue happens on an error path in __xfrm_policy_check(). When the fetching process of the object `pols[1]` fails, the function simply returns 0, forgetting to decrement the reference count of `pols[0]`, which is incremented earlier by either xfrm_sk_policy_lookup() or xfrm_policy_lookup(). This may result in memory leaks. Fix it by decreasing the reference count of `pols[0]` in that path.

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rxrpc: Fix locking in rxrpc's sendmsg

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix locking in rxrpc's sendmsg Fix three bugs in the rxrpc's sendmsg implementation: (1) rxrpc_new_client_call() should release the socket lock when returning an error from rxrpc_get_call_slot(). (2) rxrpc_wait_for_tx_window_intr() will return without the call mutex held in the event that we're interrupted by a signal whilst waiting for tx space on the socket or relocking the call mutex afterwards. Fix this by: (a) moving the unlock/lock of the call mutex up to rxrpc_send_data() such that the lock is not held around all of rxrpc_wai

loop: Check for overflow while configuring loop

In the Linux kernel, the following vulnerability has been resolved: loop: Check for overflow while configuring loop The userspace can configure a loop using an ioctl call, wherein a configuration of type loop_config is passed (see lo_ioctl()'s case on line 1550 of drivers/block/loop.c). This proceeds to call loop_configure() which in turn calls loop_set_status_from_info() (see line 1050 of loop.c), passing &config->info which is of type loop_info64*. This function then sets the appropriate values, like the offset. loop_device has lo_offset of type loff_t (see line 52 of loop.c), which is typdef-chained to long long, whereas loop_info64 has

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s390: fix double free of GS and RI CBs on fork() failure

In the Linux kernel, the following vulnerability has been resolved: s390: fix double free of GS and RI CBs on fork() failure The pointers for guarded storage and runtime instrumentation control blocks are stored in the thread_struct of the associated task. These pointers are initially copied on fork() via arch_dup_task_struct() and then cleared via copy_thread() before fork() returns. If fork() happens to fail after the initial task dup and before copy_thread(), the newly allocated task and associated thread_struct memory are freed via free_task() -> arch_release_task_struct(). This results in a double free of the guarded storage and runtim

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xen/privcmd: fix error exit of privcmd_ioctl_dm_op()

In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix error exit of privcmd_ioctl_dm_op() The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() potentially with pages being NULL, leading to a NULL dereference. Additionally lock_pages() doesn't check for pin_user_pages_fast() having been completely successful, resulting in potentially not locking all pages into memory. This could result in sporadic failures when using the related memory in user mode. Fix all of that by calling unlock_pages() always with the real number of pinned pages, which will be zero in case pages being NULL, and by checking t

md: call __md_stop_writes in md_stop

In the Linux kernel, the following vulnerability has been resolved: md: call __md_stop_writes in md_stop From the link [1], we can see raid1d was running even after the path raid_dtr -> md_stop -> __md_stop. Let's stop write first in destructor to align with normal md-raid to fix the KASAN issue. [1]. https://lore.kernel.org/linux-raid/CAPhsuW5gc4AakdGNdF8ubpezAuDLFOYUO_sfMZcec6hQFm8nhg@mail.gmail.com/T/#m7f12bf90481c02c6d2da68c64aeed4779b7df74a

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scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq

In the Linux kernel, the following vulnerability has been resolved: scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq storvsc_error_wq workqueue should not be marked as WQ_MEM_RECLAIM as it doesn't need to make forward progress under memory pressure. Marking this workqueue as WQ_MEM_RECLAIM may cause deadlock while flushing a non-WQ_MEM_RECLAIM workqueue. In the current state it causes the following warning: [ 14.506347] ------------[ cut here ]------------ [ 14.506354] workqueue: WQ_MEM_RECLAIM storvsc_error_wq_0:storvsc_remove_lun is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn [ 14.506360] WARNING

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media: pvrusb2: fix memory leak in pvr_probe

In the Linux kernel, the following vulnerability has been resolved: media: pvrusb2: fix memory leak in pvr_probe The error handling code in pvr2_hdw_create forgets to unregister the v4l2 device. When pvr2_hdw_create returns back to pvr2_context_create, it calls pvr2_context_destroy to destroy context, but mp->hdw is NULL, which leads to that pvr2_hdw_destroy directly returns. Fix this by adding v4l2_device_unregister to decrease the refcount of usb interface.

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HID: hidraw: fix memory leak in hidraw_release()

In the Linux kernel, the following vulnerability has been resolved: HID: hidraw: fix memory leak in hidraw_release() Free the buffered reports before deleting the list entry. BUG: memory leak unreferenced object 0xffff88810e72f180 (size 32): comm "softirq", pid 0, jiffies 4294945143 (age 16.080s) hex dump (first 32 bytes): 64 f3 c6 6a d1 88 07 04 00 00 00 00 00 00 00 00 d..j............ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff814ac6c3>] kmemdup+0x23/0x50 mm/util.c:128 [<ffffffff8357c1d2>] kmemdup include/linux/fortify-string.h:440 [inline] [<ffffffff8357c1d2>] hidraw

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USB: gadget: Fix use-after-free Read in usb_udc_uevent()

In the Linux kernel, the following vulnerability has been resolved: USB: gadget: Fix use-after-free Read in usb_udc_uevent() The syzbot fuzzer found a race between uevent callbacks and gadget driver unregistration that can cause a use-after-free bug: --------------------------------------------------------------- BUG: KASAN: use-after-free in usb_udc_uevent+0x11f/0x130 drivers/usb/gadget/udc/core.c:1732 Read of size 8 at addr ffff888078ce2050 by task udevd/2968 CPU: 1 PID: 2968 Comm: udevd Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace:

fbdev: fb_pm2fb: Avoid potential divide by zero error

In the Linux kernel, the following vulnerability has been resolved: fbdev: fb_pm2fb: Avoid potential divide by zero error In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be copied from user, then go through `fb_set_var()` and `info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`. Along the path, `var->pixclock` won't be modified. This function checks whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is zero, there will be a divide by zero error. So, it is necessary to check whether denominator is zero to avoid crash. As this bug is found by Syzkaller, logs are listed below. divide e

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ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftr

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bpf: Don't redirect packets with invalid pkt_len

In the Linux kernel, the following vulnerability has been resolved: bpf: Don't redirect packets with invalid pkt_len Syzbot found an issue [1]: fq_codel_drop() try to drop a flow whitout any skbs, that is, the flow->head is null. The root cause, as the [2] says, is because that bpf_prog_test_run_skb() run a bpf prog which redirects empty skbs. So we should determine whether the length of the packet modified by bpf prog or others like bpf_prog_test is valid before forwarding it directly.

drm/amd/display: clear optc underflow before turn off odm clock

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: clear optc underflow before turn off odm clock [Why] After ODM clock off, optc underflow bit will be kept there always and clear not work. We need to clear that before clock off. [How] Clear that if have when clock off.

bpf: Fix a data-race around bpf_jit_limit.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a data-race around bpf_jit_limit. While reading bpf_jit_limit, it can be changed concurrently via sysctl, WRITE_ONCE() in __do_proc_doulongvec_minmax(). The size of bpf_jit_limit is long, so we need to add a paired READ_ONCE() to avoid load-tearing.

kcm: fix strp_init() order and cleanup

In the Linux kernel, the following vulnerability has been resolved: kcm: fix strp_init() order and cleanup strp_init() is called just a few lines above this csk->sk_user_data check, it also initializes strp->work etc., therefore, it is unnecessary to call strp_done() to cancel the freshly initialized work. And if sk_user_data is already used by KCM, psock->strp should not be touched, particularly strp->work state, so we need to move strp_init() after the csk->sk_user_data check. This also makes a lockdep warning reported by syzbot go away.

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staging: rtl8712: fix use after free bugs

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8712: fix use after free bugs _Read/Write_MACREG callbacks are NULL so the read/write_macreg_hdl() functions don't do anything except free the "pcmd" pointer. It results in a use after free. Delete them.

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Input: iforce - wake up after clearing IFORCE_XMIT_RUNNING flag

In the Linux kernel, the following vulnerability has been resolved: Input: iforce - wake up after clearing IFORCE_XMIT_RUNNING flag syzbot is reporting hung task at __input_unregister_device() [1], for iforce_close() waiting at wait_event_interruptible() with dev->mutex held is blocking input_disconnect_device() from __input_unregister_device(). It seems that the cause is simply that commit c2b27ef672992a20 ("Input: iforce - wait for command completion when closing the device") forgot to call wake_up() after clear_bit(). Fix this problem by introducing a helper that calls clear_bit() followed by wake_up_all().