4.14.266-rc1 review

From: luofei <[email protected]>

When fd0e786d9d09 ("x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages") was backported to 4.14.y, the logic was reversed when calling memory_failure() to determine whether it needs to unmap the kernel page. Only when memory_failure() returns successfully, the kernel page can be unmapped.

---
 arch/x86/kernel/cpu/mcheck/mce.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -589,7 +589,7 @@ static int srao_decode_notifier(struct n
 
 	if (mce_usable_address(mce) && (mce->severity == MCE_AO_SEVERITY)) {
 		pfn = mce->addr >> PAGE_SHIFT;
-		if (memory_failure(pfn, MCE_VECTOR, 0))
+		if (!memory_failure(pfn, MCE_VECTOR, 0))
 			mce_unmap_kpfn(pfn);
 	}
 

From: Eric W. Biederman <[email protected]>

commit 24f6008564183aa120d07c03d9289519c2fe02af upstream.

The cgroup release_agent is called with call_usermodehelper. The function call_usermodehelper starts the release_agent with a full set fo capabilities. Therefore require capabilities when setting the release_agaent.

---
 kernel/cgroup/cgroup-v1.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

@@ -577,6 +577,14 @@ static ssize_t cgroup_release_agent_writ
 
 	BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
 
+	/*
+	 * Release agent gets called with all capabilities,
+	 * require capabilities to set release agent.
+	 */
+	if ((of->file->f_cred->user_ns != &init_user_ns) ||
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
 	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
 		return -ENODEV;

@@ -1060,6 +1068,7 @@ static int cgroup1_remount(struct kernfs
 {
 	int ret = 0;
 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);
+	struct cgroup_namespace *ns = current->nsproxy->cgroup_ns;
 	struct cgroup_sb_opts opts;
 	u16 added_mask, removed_mask;
 

@@ -1073,6 +1082,12 @@ static int cgroup1_remount(struct kernfs
 	if (opts.subsys_mask != root->subsys_mask || opts.release_agent)
 		pr_warn("option changes via remount are deprecated (pid=%d comm=%s)\n",
 			task_tgid_nr(current), current->comm);
+	/* See cgroup1_mount release_agent handling */
+	if (opts.release_agent &&
+	    ((ns->user_ns != &init_user_ns) || !capable(CAP_SYS_ADMIN))) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
 
 	added_mask = opts.subsys_mask & ~root->subsys_mask;
 	removed_mask = root->subsys_mask & ~opts.subsys_mask;

@@ -1236,6 +1251,15 @@ struct dentry *cgroup1_mount(struct file
 		ret = -EPERM;
 		goto out_unlock;
 	}
+	/*
+	 * Release agent gets called with all capabilities,
+	 * require capabilities to set release agent.
+	 */
+	if (opts.release_agent &&
+	    ((ns->user_ns != &init_user_ns) || !capable(CAP_SYS_ADMIN))) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
 
 	root = kzalloc(sizeof(*root), GFP_KERNEL);
 	if (!root) {

This is the start of the stable review cycle for the 4.14.266 release. There are 3 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.

Responses should be made by Fri, 11 Feb 2022 19:12:41 +0000. Anything received after that time might be too late.

The whole patch series can be found in one patch at:

	https://www.kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.14.266-rc1.gz

or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.14.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <[email protected]>

    Linux 4.14.266-rc1

luofei <[email protected]>
x86/mm, mm/hwpoison: Fix the unmap kernel 1:1 pages check condition

Greg Kroah-Hartman <[email protected]>
moxart: fix potential use-after-free on remove path

Eric W. Biederman <[email protected]>
cgroup-v1: Require capabilities to set release_agent

-------------

Diffstat:

 Makefile                         |  4 ++--
 arch/x86/kernel/cpu/mcheck/mce.c |  2 +-
 drivers/mmc/host/moxart-mmc.c    |  2 +-
 kernel/cgroup/cgroup-v1.c        | 24 ++++++++++++++++++++++++
 4 files changed, 28 insertions(+), 4 deletions(-)

From: Greg Kroah-Hartman <[email protected]>

commit bd2db32e7c3e35bd4d9b8bbff689434a50893546 upstream.

It was reported that the mmc host structure could be accessed after it was freed in moxart_remove(), so fix this by saving the base register of the device and using it instead of the pointer dereference.

---
 drivers/mmc/host/moxart-mmc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -696,12 +696,12 @@ static int moxart_remove(struct platform
 		if (!IS_ERR(host->dma_chan_rx))
 			dma_release_channel(host->dma_chan_rx);
 		mmc_remove_host(mmc);
-		mmc_free_host(mmc);
 
 		writel(0, host->base + REG_INTERRUPT_MASK);
 		writel(0, host->base + REG_POWER_CONTROL);
 		writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
 		       host->base + REG_CLOCK_CONTROL);
+		mmc_free_host(mmc);
 	}
 	return 0;
 }

All tests passing for Tegra ...

Test results for stable-v4.14:

    8 builds:	8 pass, 0 fail
    16 boots:	16 pass, 0 fail
    32 tests:	32 pass, 0 fail

Linux version: 4.14.266-rc1-g11dfe0b41849
Boards tested: tegra124-jetson-tk1, tegra20-ventana,

                tegra210-p2371-2180, tegra30-cardhu-a04

Jon

Results from Linaro’s test farm.
No regressions on arm64, arm, x86_64, and i386.

## Build
* kernel: 4.14.266-rc1
* git: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc
* git branch: linux-4.14.y
* git commit: 11dfe0b418492a0075056a9db72fd2a34628c1cd
* git describe: v4.14.264-74-g11dfe0b41849
* test details:
https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-4.14.y/build/v4.14.264-74-g11dfe0b41849

## Test Regressions (compared to v4.14.264-70-g1d3edcc1650d) No test regressions found.

## Metric Regressions (compared to v4.14.264-70-g1d3edcc1650d) No metric regressions found.

## Test Fixes (compared to v4.14.264-70-g1d3edcc1650d) No test fixes found.

## Metric Fixes (compared to v4.14.264-70-g1d3edcc1650d) No metric fixes found.

## Test result summary
total: 52019, pass: 43671, fail: 273, skip: 7413, xfail: 662

## Build Summary
* arm: 126 total, 118 passed, 8 failed
* arm64: 32 total, 32 passed, 0 failed
* i386: 18 total, 18 passed, 0 failed
* mips: 22 total, 22 passed, 0 failed
* powerpc: 52 total, 0 passed, 52 failed
* sparc: 12 total, 12 passed, 0 failed
* x86_64: 31 total, 31 passed, 0 failed

## Test suites summary
* fwts
* kselftest-android
* kselftest-breakpoints
* kselftest-capabilities
* kselftest-cgroup
* kselftest-clone3
* kselftest-core
* kselftest-cpu-hotplug
* kselftest-cpufreq
* kselftest-drivers
* kselftest-efivarfs
* kselftest-filesystems
* kselftest-firmware
* kselftest-fpu
* kselftest-futex
* kselftest-gpio
* kselftest-intel_pstate
* kselftest-ipc
* kselftest-ir
* kselftest-kcmp
* kselftest-kvm
* kselftest-lib
* kselftest-livepatch
* kselftest-membarrier
* kselftest-net
* kselftest-netfilter
* kselftest-nsfs
* kselftest-openat2
* kselftest-pid_namespace
* kselftest-pidfd
* kselftest-proc
* kselftest-pstore
* kselftest-ptrace
* kselftest-rseq
* kselftest-rtc
* kselftest-seccomp
* kselftest-sigaltstack
* kselftest-size
* kselftest-splice
* kselftest-static_keys
* kselftest-sync
* kselftest-sysctl
* kselftest-timens
* kselftest-timers
* kselftest-tmpfs
* kselftest-tpm2
* kselftest-user
* kselftest-vm
* kselftest-x86
* kselftest-zram
* kvm-unit-tests
* libhugetlbfs
* linux-log-parser
* ltp-cap_bounds-tests
* ltp-commands-tests
* ltp-containers-tests
* ltp-controllers-tests
* ltp-cpuhotplug-tests
* ltp-crypto-tests
* ltp-cve-tests
* ltp-dio-tests
* ltp-fcntl-locktests-tests
* ltp-filecaps-tests
* ltp-fs-tests
* ltp-fs_bind-tests
* ltp-fs_perms_simple-tests
* ltp-fsx-tests
* ltp-hugetlb-tests
* ltp-io-tests
* ltp-ipc-tests
* ltp-math-tests
* ltp-mm-tests
* ltp-nptl-tests
* ltp-open-posix-tests
* ltp-pty-tests
* ltp-sched-tests
* ltp-securebits-tests
* ltp-syscalls-tests
* ltp-tracing-tests
* network-basic-tests
* packetdrill
* rcutorture
* v4l2-compliance

--
Linaro LKFT
https://lkft.linaro.org

Compiled and booted 4.14.266-rc1 on my x86_64 test system successfully without errors or regressions.

Thanks,
Slade

Build results:

	total: 168 pass: 168 fail: 0
Qemu test results:
	total: 424 pass: 424 fail: 0

Guenter