CVSS: 6.3EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47189 – btrfs: fix memory ordering between normal and ordered work functions
https://notcve.org/view.php?id=CVE-2021-47189
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix memory ordering between normal and ordered work functions Ordered work functions aren't guaranteed to be handled by the same thread which executed the normal work functions. The only way execution between normal/ordered functions is synchronized is via the WORK_DONE_BIT, unfortunately the used bitops don't guarantee any ordering whatsoever. This manifested as seemingly inexplicable crashes on ARM64, where async_chunk::inode is seen as non-null in async_cow_submit which causes submit_compressed_extents to be called and crash occurs because async_chunk::inode suddenly became NULL. The call trace was similar to: pc : submit_compressed_extents+0x38/0x3d0 lr : async_cow_submit+0x50/0xd0 sp : ffff800015d4bc20 <registers omitted for brevity> Call trace: submit_compressed_extents+0x38/0x3d0 async_cow_submit+0x50/0xd0 run_ordered_work+0xc8/0x280 btrfs_work_helper+0x98/0x250 process_one_work+0x1f0/0x4ac worker_thread+0x188/0x504 kthread+0x110/0x114 ret_from_fork+0x10/0x18 Fix this by adding respective barrier calls which ensure that all accesses preceding setting of WORK_DONE_BIT are strictly ordered before setting the flag. At the same time add a read barrier after reading of WORK_DONE_BIT in run_ordered_work which ensures all subsequent loads would be strictly ordered after reading the bit. This in turn ensures are all accesses before WORK_DONE_BIT are going to be strictly ordered before any access that can occur in ordered_func. • https://git.kernel.org/stable/c/08a9ff3264181986d1d692a4e6fce3669700c9f8 https://git.kernel.org/stable/c/bd660a20fea3ec60a49709ef5360f145ec0fe779 https://git.kernel.org/stable/c/637d652d351fd4f263ef302dc52f3971d314e500 https://git.kernel.org/stable/c/804a9d239ae9cbe88e861a7cd62319cc6ec7b136 https://git.kernel.org/stable/c/ed058d735a70f4b063323f1a7bb33cda0f987513 https://git.kernel.org/stable/c/670f6b3867c8f0f11e5097f353b164cecfec6179 https://git.kernel.org/stable/c/6adbc07ebcaf8bead08b21687d49e0fc94400987 https://git.kernel.org/stable/c/47e6f9f69153247109042010f3a77579e •
CVSS: -EPSS: 0%CPEs: 2EXPL: 0CVE-2021-47188 – scsi: ufs: core: Improve SCSI abort handling
https://notcve.org/view.php?id=CVE-2021-47188
In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Improve SCSI abort handling The following has been observed on a test setup: WARNING: CPU: 4 PID: 250 at drivers/scsi/ufs/ufshcd.c:2737 ufshcd_queuecommand+0x468/0x65c Call trace: ufshcd_queuecommand+0x468/0x65c scsi_send_eh_cmnd+0x224/0x6a0 scsi_eh_test_devices+0x248/0x418 scsi_eh_ready_devs+0xc34/0xe58 scsi_error_handler+0x204/0x80c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 That warning is triggered by the following statement: WARN_ON(lrbp->cmd); Fix this warning by clearing lrbp->cmd from the abort handler. • https://git.kernel.org/stable/c/7a3e97b0dc4bbac2ba7803564ab0057722689921 https://git.kernel.org/stable/c/c36baca06efa833adaefba61f45fefdc49b6d070 https://git.kernel.org/stable/c/3ff1f6b6ba6f97f50862aa50e79959cc8ddc2566 •
CVSS: -EPSS: 0%CPEs: 4EXPL: 0CVE-2021-47187 – arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency
https://notcve.org/view.php?id=CVE-2021-47187
In the Linux kernel, the following vulnerability has been resolved: arm64: dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency The entry/exit latency and minimum residency in state for the idle states of MSM8998 were ..bad: first of all, for all of them the timings were written for CPU sleep but the min-residency-us param was miscalculated (supposedly, while porting this from downstream); Then, the power collapse states are setting PC on both the CPU cluster *and* the L2 cache, which have different timings: in the specific case of L2 the times are higher so these ones should be taken into account instead of the CPU ones. This parameter misconfiguration was not giving particular issues because on MSM8998 there was no CPU scaling at all, so cluster/L2 power collapse was rarely (if ever) hit. When CPU scaling is enabled, though, the wrong timings will produce SoC unstability shown to the user as random, apparently error-less, sudden reboots and/or lockups. This set of parameters are stabilizing the SoC when CPU scaling is ON and when power collapse is frequently hit. • https://git.kernel.org/stable/c/a14d7038ea201c5526375becfc43b9ba281b1e82 https://git.kernel.org/stable/c/e52fecdd0c142b95c720683885b06ee3f0e065c8 https://git.kernel.org/stable/c/118c826ef8b43efe0fda8faf419673707ee8c5e5 https://git.kernel.org/stable/c/3f1dcaff642e75c1d2ad03f783fa8a3b1f56dd50 •
CVSS: 7.5EPSS: 0%CPEs: 3EXPL: 0CVE-2021-47186 – tipc: check for null after calling kmemdup
https://notcve.org/view.php?id=CVE-2021-47186
In the Linux kernel, the following vulnerability has been resolved: tipc: check for null after calling kmemdup kmemdup can return a null pointer so need to check for it, otherwise the null key will be dereferenced later in tipc_crypto_key_xmit as can be seen in the trace [1]. [1] https://syzkaller.appspot.com/bug?id=bca180abb29567b189efdbdb34cbf7ba851c2a58 • https://git.kernel.org/stable/c/fc1b6d6de2208774efd2a20bf0daddb02d18b1e0 https://git.kernel.org/stable/c/a7d91625863d4ffed63b993b5e6dc1298b6430c9 https://git.kernel.org/stable/c/9404c4145542c23019a80ab1bb2ecf73cd057b10 https://git.kernel.org/stable/c/3e6db079751afd527bf3db32314ae938dc571916 • CWE-690: Unchecked Return Value to NULL Pointer Dereference •
CVSS: 4.4EPSS: 0%CPEs: 8EXPL: 0CVE-2021-47185 – tty: tty_buffer: Fix the softlockup issue in flush_to_ldisc
https://notcve.org/view.php?id=CVE-2021-47185
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. • https://git.kernel.org/stable/c/0380f643f3a7a61b0845cdc738959c2ad5735d61 https://git.kernel.org/stable/c/b1ffc16ec05ae40d82b6e373322d62e9d6b54fbc https://git.kernel.org/stable/c/4c1623651a0936ee197859824cdae6ebbd04d3ed https://git.kernel.org/stable/c/4f300f47dbcf9c3d4b2ea76c8554c8f360400725 https://git.kernel.org/stable/c/d491c84df5c469dd9621863b6a770b3428137063 https://git.kernel.org/stable/c/77e9fed33056f2a88eba9dd4d2d5412f0c7d1f41 https://git.kernel.org/stable/c/5c34486f04700f1ba04907231dce0cc2705c2d7d https://git.kernel.org/stable/c/3968ddcf05fb4b9409cd1859feb06a5b0 • CWE-1050: Excessive Platform Resource Consumption within a Loop •