The CentOS Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS6:CLSA-2025:1761139764 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: pid: take a reference when     initializing `cad_pid` During boot, kernel_init_freeable() initializes `cad_pid` to the init task's struct     pid. Later on, we may change `cad_pid` via a sysctl, and when this happens proc_do_cad_pid() will     increment the refcount on the new pid via get_pid(), and will decrement the refcount on the old pid via     put_pid(). As we never called get_pid() when we initialized `cad_pid`, we decrement a reference we never     incremented, can therefore free the init task's struct pid early. As there can be dangling references to     the struct pid, we can later encounter a use-after-free (e.g. when delivering signals). This was spotted     when fuzzing v5.13-rc3 with Syzkaller, but seems to have been around since the conversion of `cad_pid` to     struct pid in commit 9ec52099e4b8 ([PATCH] replace cad_pid by a struct pid) from the pre-KASAN stone age     of v2.6.19. Fix this by getting a reference to the init task's struct pid when we assign it to `cad_pid`.
    Full KASAN splat below. ================================================================== BUG: KASAN:
    use-after-free in ns_of_pid include/linux/pid.h:153 [inline] BUG: KASAN: use-after-free in     task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509 Read of size 4 at addr ffff23794dda0004 by task syz-     executor.0/273 CPU: 1 PID: 273 Comm: syz-executor.0 Not tainted 5.12.0-00001-g9aef892b2d15 #1 Hardware     name: linux,dummy-virt (DT) Call trace: ns_of_pid include/linux/pid.h:153 [inline]     task_active_pid_ns+0xc0/0xc8 kernel/pid.c:509 do_notify_parent+0x308/0xe60 kernel/signal.c:1950     exit_notify kernel/exit.c:682 [inline] do_exit+0x2334/0x2bd0 kernel/exit.c:845 do_group_exit+0x108/0x2c8     kernel/exit.c:922 get_signal+0x4e4/0x2a88 kernel/signal.c:2781 do_signal arch/arm64/kernel/signal.c:882     [inline] do_notify_resume+0x300/0x970 arch/arm64/kernel/signal.c:936 work_pending+0xc/0x2dc Allocated by     task 0: slab_post_alloc_hook+0x50/0x5c0 mm/slab.h:516 slab_alloc_node mm/slub.c:2907 [inline] slab_alloc     mm/slub.c:2915 [inline] kmem_cache_alloc+0x1f4/0x4c0 mm/slub.c:2920 alloc_pid+0xdc/0xc00 kernel/pid.c:180     copy_process+0x2794/0x5e18 kernel/fork.c:2129 kernel_clone+0x194/0x13c8 kernel/fork.c:2500     kernel_thread+0xd4/0x110 kernel/fork.c:2552 rest_init+0x44/0x4a0 init/main.c:687     arch_call_rest_init+0x1c/0x28 start_kernel+0x520/0x554 init/main.c:1064 0x0 Freed by task 270:
    slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x98/0x260 mm/slub.c:1600 slab_free     mm/slub.c:3161 [inline] kmem_cache_free+0x224/0x8e0 mm/slub.c:3177 put_pid.part.4+0xe0/0x1a8     kernel/pid.c:114 put_pid+0x30/0x48 kernel/pid.c:109 proc_do_cad_pid+0x190/0x1b0 kernel/sysctl.c:1401     proc_sys_call_handler+0x338/0x4b0 fs/proc/proc_sysctl.c:591 proc_sys_write+0x34/0x48     fs/proc/proc_sysctl.c:617 call_write_iter include/linux/fs.h:1977 [inline] new_sync_write+0x3ac/0x510     fs/read_write.c:518 vfs_write fs/read_write.c:605 [inline] vfs_write+0x9c4/0x1018 fs/read_write.c:585     ksys_write+0x124/0x240 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write     fs/read_write.c:667 [inline] __arm64_sys_write+0x78/0xb0 fs/read_write.c:667 __invoke_syscall     arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall arch/arm64/kernel/syscall.c:49 [inline]     el0_svc_common.constprop.1+0x16c/0x388 arch/arm64/kernel/syscall.c:129 do_el0_svc+0xf8/0x150     arch/arm64/kernel/syscall.c:168 el0_svc+0x28/0x38 arch/arm64/kernel/entry-common.c:416     el0_sync_handler+0x134/0x180 arch/arm64/kernel/entry-common.c:432 el0_sync+0x154/0x180     arch/arm64/kernel/entry.S:701 The buggy address belongs to the object at ffff23794dda0000 which belongs to     the cache pid of size 224 The buggy address is located 4 bytes inside of 224-byte region [ff
    ---truncated--- (CVE-2021-47118)

  - In the Linux kernel, the following vulnerability has been resolved: i2c: i801: Don't generate an interrupt     on bus reset Now that the i2c-i801 driver supports interrupts, setting the KILL bit in a attempt to     recover from a timed out transaction triggers an interrupt. Unfortunately, the interrupt handler     (i801_isr) is not prepared for this situation and will try to process the interrupt as if it was signaling     the end of a successful transaction. In the case of a block transaction, this can result in an out-of-     range memory access. This condition was reproduced several times by syzbot:
    https://syzkaller.appspot.com/bug?extid=ed71512d469895b5b34e     https://syzkaller.appspot.com/bug?extid=8c8dedc0ba9e03f6c79e     https://syzkaller.appspot.com/bug?extid=c8ff0b6d6c73d81b610e     https://syzkaller.appspot.com/bug?extid=33f6c360821c399d69eb     https://syzkaller.appspot.com/bug?extid=be15dc0b1933f04b043a     https://syzkaller.appspot.com/bug?extid=b4d3fd1dfd53e90afd79 So disable interrupts while trying to reset     the bus. Interrupts will be enabled again for the following transaction. (CVE-2021-47153)

  - In the Linux kernel, the following vulnerability has been resolved: watchdog: Fix possible use-after-free     by calling del_timer_sync() This driver's remove path calls del_timer(). However, that function does not     wait until the timer handler finishes. This means that the timer handler may still be running after the     driver's remove function has finished, which would result in a use-after-free. Fix by calling     del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.
    (CVE-2021-47321)

  - In the Linux kernel, the following vulnerability has been resolved: virtio-net: Add validation for used     length This adds validation for used length (might come from an untrusted device) to avoid data corruption     or loss. (CVE-2021-47352)

  - In the Linux kernel, the following vulnerability has been resolved: tty: Fix out-of-bound vmalloc access     in imageblit This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the     fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this     struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(),     leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong     value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value,     eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the     resize_screen() be called even if the screen does not need any resizing, so it will fix and fill the     fb_var_screeninfo independently. (CVE-2021-47383)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

CentOS Linux 6 [TuxCare] Security Update: kernel / kernel-abi-whitelists / kernel-debug / kernel-debug-devel / etc Multiple Vulnerabilities (CENTOS6:CLSA-2025:1761139764)

high Nessus Plugin ID 351647

Version 1.2