Check out this report and any autotriaged failures in our web dashboard:
https://datawarehouse.cki-project.org/kcidb/checkouts/25602
Hello,
We ran automated tests on a recent commit from this kernel tree:
Kernel repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
Commit: b6f81f5c9c8e - cifs: nosharesock should be set on new server
The results of these automated tests are provided below.
Overall result: PASSED
Merge: OK
Compile: OK
Tests: OK
Targeted tests: NO
All kernel binaries, config files, and logs are available for download here:
https://arr-cki-prod-datawarehouse-public.s3.amazonaws.com/index.html?prefi…
Please reply to this email if you have any questions about the tests that we
ran or if you have any suggestions on how to make future tests more effective.
,-. ,-.
( C ) ( K ) Continuous
`-',-.`-' Kernel
( I ) Integration
`-'
______________________________________________________________________________
Compile testing
---------------
We compiled the kernel for 4 architectures:
aarch64:
make options: make -j24 INSTALL_MOD_STRIP=1 targz-pkg
ppc64le:
make options: make -j24 INSTALL_MOD_STRIP=1 targz-pkg
s390x:
make options: make -j24 INSTALL_MOD_STRIP=1 targz-pkg
x86_64:
make options: make -j24 INSTALL_MOD_STRIP=1 targz-pkg
Hardware testing
----------------
We booted each kernel and ran the following tests:
aarch64:
Host 1:
✅ Boot test
✅ Reboot test
🚧 ✅ Storage blktests - nvmeof-mp
Host 2:
✅ Boot test
✅ Reboot test
✅ Networking bridge: sanity - mlx5
✅ Ethernet drivers sanity - mlx5
Host 3:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
⚡⚡⚡ xfstests - ext4
⚡⚡⚡ xfstests - xfs
⚡⚡⚡ IPMI driver test
⚡⚡⚡ IPMItool loop stress test
⚡⚡⚡ selinux-policy: serge-testsuite
⚡⚡⚡ Storage blktests - blk
⚡⚡⚡ Storage block - filesystem fio test
⚡⚡⚡ Storage block - queue scheduler test
⚡⚡⚡ storage: software RAID testing
⚡⚡⚡ Storage: swraid mdadm raid_module test
⚡⚡⚡ stress: stress-ng - interrupt
⚡⚡⚡ stress: stress-ng - cpu
⚡⚡⚡ stress: stress-ng - cpu-cache
⚡⚡⚡ stress: stress-ng - memory
🚧 ⚡⚡⚡ Podman system test - as root
🚧 ⚡⚡⚡ Podman system test - as user
🚧 ⚡⚡⚡ xfstests - btrfs
🚧 ⚡⚡⚡ Storage blktests - nvme-tcp
🚧 ⚡⚡⚡ lvm cache test
🚧 ⚡⚡⚡ stress: stress-ng - os
Host 4:
✅ Boot test
✅ Reboot test
✅ ACPI table test
✅ ACPI enabled test
✅ LTP - cve
✅ LTP - sched
✅ LTP - syscalls
✅ LTP - can
✅ LTP - commands
✅ LTP - containers
✅ LTP - dio
✅ LTP - fs
✅ LTP - fsx
✅ LTP - math
✅ LTP - hugetlb
✅ LTP - mm
✅ LTP - nptl
✅ LTP - pty
✅ LTP - ipc
✅ LTP - tracing
✅ LTP: openposix test suite
✅ CIFS Connectathon
✅ POSIX pjd-fstest suites
✅ NFS Connectathon
✅ Loopdev Sanity
✅ jvm - jcstress tests
✅ Memory: fork_mem
✅ Memory function: memfd_create
✅ AMTU (Abstract Machine Test Utility)
✅ Networking bridge: sanity
✅ Ethernet drivers sanity
✅ Networking socket: fuzz
✅ Networking route: pmtu
✅ Networking route_func - local
✅ Networking route_func - forward
✅ Networking TCP: keepalive test
✅ Networking UDP: socket
✅ Networking cki netfilter test
✅ Networking tunnel: geneve basic test
✅ Networking tunnel: gre basic
✅ L2TP basic test
✅ Networking tunnel: vxlan basic
✅ Networking ipsec: basic netns - transport
✅ Networking ipsec: basic netns - tunnel
✅ Libkcapi AF_ALG test
✅ pciutils: update pci ids test
✅ ALSA PCM loopback test
✅ ALSA Control (mixer) Userspace Element test
✅ storage: dm/common
✅ lvm snapper test
✅ storage: SCSI VPD
✅ trace: ftrace/tracer
🚧 ✅ xarray-idr-radixtree-test
🚧 ✅ i2c: i2cdetect sanity
🚧 ✅ Firmware test suite
🚧 ✅ Memory function: kaslr
🚧 ✅ Networking: igmp conformance test
🚧 ✅ audit: audit testsuite test
Host 5:
✅ Boot test
✅ Reboot test
🚧 ✅ Storage blktests - srp
Host 6:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
⚡⚡⚡ xfstests - ext4
⚡⚡⚡ xfstests - xfs
⚡⚡⚡ IPMI driver test
⚡⚡⚡ IPMItool loop stress test
⚡⚡⚡ selinux-policy: serge-testsuite
⚡⚡⚡ Storage blktests - blk
⚡⚡⚡ Storage block - filesystem fio test
⚡⚡⚡ Storage block - queue scheduler test
⚡⚡⚡ storage: software RAID testing
⚡⚡⚡ Storage: swraid mdadm raid_module test
⚡⚡⚡ stress: stress-ng - interrupt
⚡⚡⚡ stress: stress-ng - cpu
⚡⚡⚡ stress: stress-ng - cpu-cache
⚡⚡⚡ stress: stress-ng - memory
🚧 ⚡⚡⚡ Podman system test - as root
🚧 ⚡⚡⚡ Podman system test - as user
🚧 ⚡⚡⚡ xfstests - btrfs
🚧 ⚡⚡⚡ Storage blktests - nvme-tcp
🚧 ⚡⚡⚡ lvm cache test
🚧 ⚡⚡⚡ stress: stress-ng - os
Host 7:
✅ Boot test
✅ Reboot test
✅ xfstests - ext4
✅ xfstests - xfs
✅ IPMI driver test
✅ IPMItool loop stress test
✅ selinux-policy: serge-testsuite
✅ Storage blktests - blk
✅ Storage block - filesystem fio test
✅ Storage block - queue scheduler test
✅ storage: software RAID testing
✅ Storage: swraid mdadm raid_module test
✅ stress: stress-ng - interrupt
✅ stress: stress-ng - cpu
✅ stress: stress-ng - cpu-cache
✅ stress: stress-ng - memory
🚧 ✅ Podman system test - as root
🚧 ❌ Podman system test - as user
🚧 ✅ xfstests - btrfs
🚧 ✅ Storage blktests - nvme-tcp
🚧 ✅ lvm cache test
🚧 ✅ stress: stress-ng - os
ppc64le:
Host 1:
✅ Boot test
✅ Reboot test
🚧 ❌ Storage blktests - srp
Host 2:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
⚡⚡⚡ LTP - cve
⚡⚡⚡ LTP - sched
⚡⚡⚡ LTP - syscalls
⚡⚡⚡ LTP - can
⚡⚡⚡ LTP - commands
⚡⚡⚡ LTP - containers
⚡⚡⚡ LTP - dio
⚡⚡⚡ LTP - fs
⚡⚡⚡ LTP - fsx
⚡⚡⚡ LTP - math
⚡⚡⚡ LTP - hugetlb
⚡⚡⚡ LTP - mm
⚡⚡⚡ LTP - nptl
⚡⚡⚡ LTP - pty
⚡⚡⚡ LTP - ipc
⚡⚡⚡ LTP - tracing
⚡⚡⚡ LTP: openposix test suite
⚡⚡⚡ CIFS Connectathon
⚡⚡⚡ POSIX pjd-fstest suites
⚡⚡⚡ NFS Connectathon
⚡⚡⚡ Loopdev Sanity
⚡⚡⚡ jvm - jcstress tests
⚡⚡⚡ Memory: fork_mem
⚡⚡⚡ Memory function: memfd_create
⚡⚡⚡ AMTU (Abstract Machine Test Utility)
⚡⚡⚡ Networking bridge: sanity
⚡⚡⚡ Ethernet drivers sanity
⚡⚡⚡ Networking socket: fuzz
⚡⚡⚡ Networking route: pmtu
⚡⚡⚡ Networking route_func - local
⚡⚡⚡ Networking route_func - forward
⚡⚡⚡ Networking TCP: keepalive test
⚡⚡⚡ Networking UDP: socket
⚡⚡⚡ Networking cki netfilter test
⚡⚡⚡ Networking tunnel: geneve basic test
⚡⚡⚡ Networking tunnel: gre basic
⚡⚡⚡ L2TP basic test
⚡⚡⚡ Networking tunnel: vxlan basic
⚡⚡⚡ Networking ipsec: basic netns - tunnel
⚡⚡⚡ Libkcapi AF_ALG test
⚡⚡⚡ pciutils: update pci ids test
⚡⚡⚡ ALSA PCM loopback test
⚡⚡⚡ ALSA Control (mixer) Userspace Element test
⚡⚡⚡ storage: dm/common
⚡⚡⚡ lvm snapper test
⚡⚡⚡ trace: ftrace/tracer
🚧 ⚡⚡⚡ xarray-idr-radixtree-test
🚧 ⚡⚡⚡ Memory function: kaslr
🚧 ⚡⚡⚡ audit: audit testsuite test
Host 3:
✅ Boot test
✅ Reboot test
✅ xfstests - ext4
✅ xfstests - xfs
✅ IPMI driver test
✅ IPMItool loop stress test
✅ selinux-policy: serge-testsuite
✅ Storage blktests - blk
✅ Storage block - filesystem fio test
✅ Storage block - queue scheduler test
✅ storage: software RAID testing
✅ Storage: swraid mdadm raid_module test
🚧 ✅ Podman system test - as root
🚧 ✅ Podman system test - as user
🚧 ✅ xfstests - btrfs
🚧 ✅ Storage blktests - nvme-tcp
🚧 ✅ Storage: lvm device-mapper test - upstream
🚧 ✅ lvm cache test
Host 4:
✅ Boot test
✅ Reboot test
🚧 ❌ Storage blktests - nvmeof-mp
Host 5:
✅ Boot test
✅ Reboot test
✅ LTP - cve
✅ LTP - sched
✅ LTP - syscalls
✅ LTP - can
✅ LTP - commands
✅ LTP - containers
✅ LTP - dio
✅ LTP - fs
✅ LTP - fsx
✅ LTP - math
✅ LTP - hugetlb
✅ LTP - mm
✅ LTP - nptl
✅ LTP - pty
✅ LTP - ipc
✅ LTP - tracing
✅ LTP: openposix test suite
✅ CIFS Connectathon
✅ POSIX pjd-fstest suites
✅ NFS Connectathon
✅ Loopdev Sanity
✅ jvm - jcstress tests
✅ Memory: fork_mem
✅ Memory function: memfd_create
✅ AMTU (Abstract Machine Test Utility)
✅ Networking bridge: sanity
✅ Ethernet drivers sanity
✅ Networking socket: fuzz
✅ Networking route: pmtu
✅ Networking route_func - local
✅ Networking route_func - forward
✅ Networking TCP: keepalive test
✅ Networking UDP: socket
✅ Networking cki netfilter test
✅ Networking tunnel: geneve basic test
✅ Networking tunnel: gre basic
✅ L2TP basic test
✅ Networking tunnel: vxlan basic
✅ Networking ipsec: basic netns - tunnel
✅ Libkcapi AF_ALG test
✅ pciutils: update pci ids test
✅ ALSA PCM loopback test
✅ ALSA Control (mixer) Userspace Element test
✅ storage: dm/common
✅ lvm snapper test
✅ trace: ftrace/tracer
🚧 ✅ xarray-idr-radixtree-test
🚧 ✅ Memory function: kaslr
🚧 ✅ audit: audit testsuite test
s390x:
Host 1:
✅ Boot test
✅ Reboot test
✅ LTP - cve
✅ LTP - sched
✅ LTP - syscalls
✅ LTP - can
✅ LTP - commands
✅ LTP - containers
✅ LTP - dio
✅ LTP - fs
✅ LTP - fsx
✅ LTP - math
✅ LTP - hugetlb
✅ LTP - mm
✅ LTP - nptl
✅ LTP - pty
✅ LTP - ipc
✅ LTP - tracing
✅ LTP: openposix test suite
✅ CIFS Connectathon
✅ POSIX pjd-fstest suites
✅ NFS Connectathon
✅ Loopdev Sanity
✅ jvm - jcstress tests
✅ Memory: fork_mem
✅ Memory function: memfd_create
✅ AMTU (Abstract Machine Test Utility)
✅ Networking bridge: sanity
✅ Ethernet drivers sanity
✅ Networking route: pmtu
✅ Networking route_func - local
✅ Networking route_func - forward
✅ Networking TCP: keepalive test
✅ Networking UDP: socket
✅ Networking cki netfilter test
✅ Networking tunnel: geneve basic test
✅ Networking tunnel: gre basic
✅ L2TP basic test
✅ Networking tunnel: vxlan basic
✅ Networking ipsec: basic netns - transport
✅ Networking ipsec: basic netns - tunnel
✅ Libkcapi AF_ALG test
✅ storage: dm/common
✅ lvm snapper test
✅ trace: ftrace/tracer
🚧 ❌ xarray-idr-radixtree-test
🚧 ✅ Memory function: kaslr
🚧 ✅ audit: audit testsuite test
Host 2:
✅ Boot test
✅ Reboot test
✅ selinux-policy: serge-testsuite
✅ Storage blktests - blk
✅ Storage: swraid mdadm raid_module test
✅ stress: stress-ng - interrupt
✅ stress: stress-ng - cpu
✅ stress: stress-ng - cpu-cache
✅ stress: stress-ng - memory
🚧 ✅ Podman system test - as root
🚧 ✅ Podman system test - as user
🚧 ✅ Storage blktests - nvme-tcp
🚧 ✅ lvm cache test
🚧 ✅ stress: stress-ng - os
Host 3:
✅ Boot test
✅ Reboot test
🚧 ✅ Storage blktests - srp
Host 4:
✅ Boot test
✅ Reboot test
🚧 ✅ Storage blktests - nvmeof-mp
x86_64:
Host 1:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
✅ Boot test
✅ Reboot test
✅ ACPI table test
✅ LTP - cve
✅ LTP - sched
✅ LTP - syscalls
✅ LTP - can
✅ LTP - commands
✅ LTP - containers
✅ LTP - dio
⚡⚡⚡ LTP - fs
⚡⚡⚡ LTP - fsx
⚡⚡⚡ LTP - math
⚡⚡⚡ LTP - hugetlb
⚡⚡⚡ LTP - mm
⚡⚡⚡ LTP - nptl
⚡⚡⚡ LTP - pty
⚡⚡⚡ LTP - ipc
⚡⚡⚡ LTP - tracing
⚡⚡⚡ LTP: openposix test suite
⚡⚡⚡ CIFS Connectathon
⚡⚡⚡ POSIX pjd-fstest suites
⚡⚡⚡ NFS Connectathon
⚡⚡⚡ Loopdev Sanity
⚡⚡⚡ jvm - jcstress tests
⚡⚡⚡ Memory: fork_mem
⚡⚡⚡ Memory function: memfd_create
⚡⚡⚡ AMTU (Abstract Machine Test Utility)
⚡⚡⚡ Networking bridge: sanity
⚡⚡⚡ Ethernet drivers sanity
⚡⚡⚡ Networking socket: fuzz
⚡⚡⚡ Networking route: pmtu
⚡⚡⚡ Networking route_func - local
⚡⚡⚡ Networking route_func - forward
⚡⚡⚡ Networking TCP: keepalive test
⚡⚡⚡ Networking UDP: socket
⚡⚡⚡ Networking cki netfilter test
⚡⚡⚡ Networking tunnel: geneve basic test
⚡⚡⚡ Networking tunnel: gre basic
⚡⚡⚡ L2TP basic test
⚡⚡⚡ Networking tunnel: vxlan basic
⚡⚡⚡ Networking ipsec: basic netns - transport
⚡⚡⚡ Networking ipsec: basic netns - tunnel
⚡⚡⚡ Libkcapi AF_ALG test
⚡⚡⚡ pciutils: sanity smoke test
⚡⚡⚡ pciutils: update pci ids test
⚡⚡⚡ ALSA PCM loopback test
⚡⚡⚡ ALSA Control (mixer) Userspace Element test
⚡⚡⚡ storage: dm/common
⚡⚡⚡ lvm snapper test
⚡⚡⚡ storage: SCSI VPD
⚡⚡⚡ trace: ftrace/tracer
🚧 ⚡⚡⚡ xarray-idr-radixtree-test
🚧 ⚡⚡⚡ i2c: i2cdetect sanity
🚧 ⚡⚡⚡ Firmware test suite
🚧 ⚡⚡⚡ Memory function: kaslr
🚧 ⚡⚡⚡ Networking: igmp conformance test
🚧 ⚡⚡⚡ audit: audit testsuite test
Host 2:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
⚡⚡⚡ xfstests - ext4
⚡⚡⚡ xfstests - xfs
⚡⚡⚡ xfstests - nfsv4.2
⚡⚡⚡ xfstests - cifsv3.11
⚡⚡⚡ IPMI driver test
⚡⚡⚡ IPMItool loop stress test
⚡⚡⚡ selinux-policy: serge-testsuite
⚡⚡⚡ power-management: cpupower/sanity test
⚡⚡⚡ Storage blktests - blk
⚡⚡⚡ Storage block - filesystem fio test
⚡⚡⚡ Storage block - queue scheduler test
⚡⚡⚡ storage: software RAID testing
⚡⚡⚡ Storage: swraid mdadm raid_module test
⚡⚡⚡ stress: stress-ng - interrupt
⚡⚡⚡ stress: stress-ng - cpu
⚡⚡⚡ stress: stress-ng - cpu-cache
⚡⚡⚡ stress: stress-ng - memory
🚧 ⚡⚡⚡ Podman system test - as root
🚧 ⚡⚡⚡ Podman system test - as user
🚧 ⚡⚡⚡ CPU: Idle Test
🚧 ⚡⚡⚡ xfstests - btrfs
🚧 ⚡⚡⚡ Storage blktests - nvme-tcp
🚧 ⚡⚡⚡ Storage: lvm device-mapper test - upstream
🚧 ⚡⚡⚡ lvm cache test
🚧 ⚡⚡⚡ stress: stress-ng - os
Host 3:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
🚧 ⚡⚡⚡ Storage blktests - srp
Host 4:
✅ Boot test
✅ Reboot test
🚧 ✅ Storage blktests - nvmeof-mp
Host 5:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
🚧 ⚡⚡⚡ Storage blktests - srp
Host 6:
⚡ Internal infrastructure issues prevented one or more tests (marked
with ⚡⚡⚡) from running on this architecture.
This is not the fault of the kernel that was tested.
⚡⚡⚡ Boot test
⚡⚡⚡ Reboot test
🚧 ⚡⚡⚡ Storage blktests - srp
Test sources: https://gitlab.com/cki-project/kernel-tests
💚 Pull requests are welcome for new tests or improvements to existing tests!
Aborted tests
-------------
Tests that didn't complete running successfully are marked with ⚡⚡⚡.
If this was caused by an infrastructure issue, we try to mark that
explicitly in the report.
Waived tests
------------
If the test run included waived tests, they are marked with 🚧. Such tests are
executed but their results are not taken into account. Tests are waived when
their results are not reliable enough, e.g. when they're just introduced or are
being fixed.
Testing timeout
---------------
We aim to provide a report within reasonable timeframe. Tests that haven't
finished running yet are marked with ⏱.
Targeted tests
--------------
Test runs for patches always include a set of base tests, plus some
tests chosen based on the file paths modified by the patch. The latter
are called "targeted tests". If no targeted tests are run, that means
no patch-specific tests are available. Please, consider contributing a
targeted test for related patches to increase test coverage. See
https://docs.engineering.redhat.com/x/_wEZB for more details.
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 85b6d24646e4125c591639841169baa98a2da503 Mon Sep 17 00:00:00 2001
From: Alexander Mikhalitsyn <alexander.mikhalitsyn(a)virtuozzo.com>
Date: Fri, 19 Nov 2021 16:43:21 -0800
Subject: [PATCH] shm: extend forced shm destroy to support objects from
several IPC nses
Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.
This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).
This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.
To achieve that we do several things:
1. add a namespace (non-refcounted) pointer to the struct shmid_kernel
2. during new shm object creation (newseg()/shmget syscall) we
initialize this pointer by current task IPC ns
3. exit_shm() fully reworked such that it traverses over all shp's in
task->sysvshm.shm_clist and gets IPC namespace not from current task
as it was before but from shp's object itself, then call
shm_destroy(shp, ns).
Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed. To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".
Q/A
Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
lifetime, so, if we get shp object from the task->sysvshm.shm_clist
while holding task_lock(task) nobody can steal our namespace.
Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
namespace without getting task->sysvshm.shm_clist list cleaned up.
Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife…
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ab602f79915 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: Manfred Spraul <manfred(a)colorfullife.com>
Signed-off-by: Manfred Spraul <manfred(a)colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn(a)virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Davidlohr Bueso <dave(a)stgolabs.net>
Cc: Greg KH <gregkh(a)linuxfoundation.org>
Cc: Andrei Vagin <avagin(a)gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Cc: Vasily Averin <vvs(a)virtuozzo.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 05e22770af51..b75395ec8d52 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -131,6 +131,16 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
return ns;
}
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+ if (ns) {
+ if (refcount_inc_not_zero(&ns->ns.count))
+ return ns;
+ }
+
+ return NULL;
+}
+
extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
@@ -147,6 +157,11 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
return ns;
}
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+ return ns;
+}
+
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index ba88a6987400..058d7f371e25 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -158,7 +158,7 @@ static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
* Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
* pins the final release of task.io_context. Also protects ->cpuset and
- * ->cgroup.subsys[]. And ->vfork_done.
+ * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
*
* Nests both inside and outside of read_lock(&tasklist_lock).
* It must not be nested with write_lock_irq(&tasklist_lock),
diff --git a/ipc/shm.c b/ipc/shm.c
index 4942bdd65748..b3048ebd5c31 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -62,9 +62,18 @@ struct shmid_kernel /* private to the kernel */
struct pid *shm_lprid;
struct ucounts *mlock_ucounts;
- /* The task created the shm object. NULL if the task is dead. */
+ /*
+ * The task created the shm object, for
+ * task_lock(shp->shm_creator)
+ */
struct task_struct *shm_creator;
- struct list_head shm_clist; /* list by creator */
+
+ /*
+ * List by creator. task_lock(->shm_creator) required for read/write.
+ * If list_empty(), then the creator is dead already.
+ */
+ struct list_head shm_clist;
+ struct ipc_namespace *ns;
} __randomize_layout;
/* shm_mode upper byte flags */
@@ -115,6 +124,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
struct shmid_kernel *shp;
shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ WARN_ON(ns != shp->ns);
if (shp->shm_nattch) {
shp->shm_perm.mode |= SHM_DEST;
@@ -225,10 +235,43 @@ static void shm_rcu_free(struct rcu_head *head)
kfree(shp);
}
-static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
+/*
+ * It has to be called with shp locked.
+ * It must be called before ipc_rmid()
+ */
+static inline void shm_clist_rm(struct shmid_kernel *shp)
{
- list_del(&s->shm_clist);
- ipc_rmid(&shm_ids(ns), &s->shm_perm);
+ struct task_struct *creator;
+
+ /* ensure that shm_creator does not disappear */
+ rcu_read_lock();
+
+ /*
+ * A concurrent exit_shm may do a list_del_init() as well.
+ * Just do nothing if exit_shm already did the work
+ */
+ if (!list_empty(&shp->shm_clist)) {
+ /*
+ * shp->shm_creator is guaranteed to be valid *only*
+ * if shp->shm_clist is not empty.
+ */
+ creator = shp->shm_creator;
+
+ task_lock(creator);
+ /*
+ * list_del_init() is a nop if the entry was already removed
+ * from the list.
+ */
+ list_del_init(&shp->shm_clist);
+ task_unlock(creator);
+ }
+ rcu_read_unlock();
+}
+
+static inline void shm_rmid(struct shmid_kernel *s)
+{
+ shm_clist_rm(s);
+ ipc_rmid(&shm_ids(s->ns), &s->shm_perm);
}
@@ -283,7 +326,7 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
shm_file = shp->shm_file;
shp->shm_file = NULL;
ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
- shm_rmid(ns, shp);
+ shm_rmid(shp);
shm_unlock(shp);
if (!is_file_hugepages(shm_file))
shmem_lock(shm_file, 0, shp->mlock_ucounts);
@@ -303,10 +346,10 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
*
* 2) sysctl kernel.shm_rmid_forced is set to 1.
*/
-static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+static bool shm_may_destroy(struct shmid_kernel *shp)
{
return (shp->shm_nattch == 0) &&
- (ns->shm_rmid_forced ||
+ (shp->ns->shm_rmid_forced ||
(shp->shm_perm.mode & SHM_DEST));
}
@@ -337,7 +380,7 @@ static void shm_close(struct vm_area_struct *vma)
ipc_update_pid(&shp->shm_lprid, task_tgid(current));
shp->shm_dtim = ktime_get_real_seconds();
shp->shm_nattch--;
- if (shm_may_destroy(ns, shp))
+ if (shm_may_destroy(shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);
@@ -358,10 +401,10 @@ static int shm_try_destroy_orphaned(int id, void *p, void *data)
*
* As shp->* are changed under rwsem, it's safe to skip shp locking.
*/
- if (shp->shm_creator != NULL)
+ if (!list_empty(&shp->shm_clist))
return 0;
- if (shm_may_destroy(ns, shp)) {
+ if (shm_may_destroy(shp)) {
shm_lock_by_ptr(shp);
shm_destroy(ns, shp);
}
@@ -379,48 +422,97 @@ void shm_destroy_orphaned(struct ipc_namespace *ns)
/* Locking assumes this will only be called with task == current */
void exit_shm(struct task_struct *task)
{
- struct ipc_namespace *ns = task->nsproxy->ipc_ns;
- struct shmid_kernel *shp, *n;
+ for (;;) {
+ struct shmid_kernel *shp;
+ struct ipc_namespace *ns;
- if (list_empty(&task->sysvshm.shm_clist))
- return;
+ task_lock(task);
+
+ if (list_empty(&task->sysvshm.shm_clist)) {
+ task_unlock(task);
+ break;
+ }
+
+ shp = list_first_entry(&task->sysvshm.shm_clist, struct shmid_kernel,
+ shm_clist);
- /*
- * If kernel.shm_rmid_forced is not set then only keep track of
- * which shmids are orphaned, so that a later set of the sysctl
- * can clean them up.
- */
- if (!ns->shm_rmid_forced) {
- down_read(&shm_ids(ns).rwsem);
- list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
- shp->shm_creator = NULL;
/*
- * Only under read lock but we are only called on current
- * so no entry on the list will be shared.
+ * 1) Get pointer to the ipc namespace. It is worth to say
+ * that this pointer is guaranteed to be valid because
+ * shp lifetime is always shorter than namespace lifetime
+ * in which shp lives.
+ * We taken task_lock it means that shp won't be freed.
*/
- list_del(&task->sysvshm.shm_clist);
- up_read(&shm_ids(ns).rwsem);
- return;
- }
+ ns = shp->ns;
- /*
- * Destroy all already created segments, that were not yet mapped,
- * and mark any mapped as orphan to cover the sysctl toggling.
- * Destroy is skipped if shm_may_destroy() returns false.
- */
- down_write(&shm_ids(ns).rwsem);
- list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
- shp->shm_creator = NULL;
+ /*
+ * 2) If kernel.shm_rmid_forced is not set then only keep track of
+ * which shmids are orphaned, so that a later set of the sysctl
+ * can clean them up.
+ */
+ if (!ns->shm_rmid_forced)
+ goto unlink_continue;
- if (shm_may_destroy(ns, shp)) {
- shm_lock_by_ptr(shp);
- shm_destroy(ns, shp);
+ /*
+ * 3) get a reference to the namespace.
+ * The refcount could be already 0. If it is 0, then
+ * the shm objects will be free by free_ipc_work().
+ */
+ ns = get_ipc_ns_not_zero(ns);
+ if (!ns) {
+unlink_continue:
+ list_del_init(&shp->shm_clist);
+ task_unlock(task);
+ continue;
}
- }
- /* Remove the list head from any segments still attached. */
- list_del(&task->sysvshm.shm_clist);
- up_write(&shm_ids(ns).rwsem);
+ /*
+ * 4) get a reference to shp.
+ * This cannot fail: shm_clist_rm() is called before
+ * ipc_rmid(), thus the refcount cannot be 0.
+ */
+ WARN_ON(!ipc_rcu_getref(&shp->shm_perm));
+
+ /*
+ * 5) unlink the shm segment from the list of segments
+ * created by current.
+ * This must be done last. After unlinking,
+ * only the refcounts obtained above prevent IPC_RMID
+ * from destroying the segment or the namespace.
+ */
+ list_del_init(&shp->shm_clist);
+
+ task_unlock(task);
+
+ /*
+ * 6) we have all references
+ * Thus lock & if needed destroy shp.
+ */
+ down_write(&shm_ids(ns).rwsem);
+ shm_lock_by_ptr(shp);
+ /*
+ * rcu_read_lock was implicitly taken in shm_lock_by_ptr, it's
+ * safe to call ipc_rcu_putref here
+ */
+ ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
+
+ if (ipc_valid_object(&shp->shm_perm)) {
+ if (shm_may_destroy(shp))
+ shm_destroy(ns, shp);
+ else
+ shm_unlock(shp);
+ } else {
+ /*
+ * Someone else deleted the shp from namespace
+ * idr/kht while we have waited.
+ * Just unlock and continue.
+ */
+ shm_unlock(shp);
+ }
+
+ up_write(&shm_ids(ns).rwsem);
+ put_ipc_ns(ns); /* paired with get_ipc_ns_not_zero */
+ }
}
static vm_fault_t shm_fault(struct vm_fault *vmf)
@@ -676,7 +768,11 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
if (error < 0)
goto no_id;
+ shp->ns = ns;
+
+ task_lock(current);
list_add(&shp->shm_clist, ¤t->sysvshm.shm_clist);
+ task_unlock(current);
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
@@ -1567,7 +1663,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
down_write(&shm_ids(ns).rwsem);
shp = shm_lock(ns, shmid);
shp->shm_nattch--;
- if (shm_may_destroy(ns, shp))
+
+ if (shm_may_destroy(shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 85b6d24646e4125c591639841169baa98a2da503 Mon Sep 17 00:00:00 2001
From: Alexander Mikhalitsyn <alexander.mikhalitsyn(a)virtuozzo.com>
Date: Fri, 19 Nov 2021 16:43:21 -0800
Subject: [PATCH] shm: extend forced shm destroy to support objects from
several IPC nses
Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.
This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).
This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.
To achieve that we do several things:
1. add a namespace (non-refcounted) pointer to the struct shmid_kernel
2. during new shm object creation (newseg()/shmget syscall) we
initialize this pointer by current task IPC ns
3. exit_shm() fully reworked such that it traverses over all shp's in
task->sysvshm.shm_clist and gets IPC namespace not from current task
as it was before but from shp's object itself, then call
shm_destroy(shp, ns).
Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed. To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".
Q/A
Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
lifetime, so, if we get shp object from the task->sysvshm.shm_clist
while holding task_lock(task) nobody can steal our namespace.
Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
namespace without getting task->sysvshm.shm_clist list cleaned up.
Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife…
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ab602f79915 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: Manfred Spraul <manfred(a)colorfullife.com>
Signed-off-by: Manfred Spraul <manfred(a)colorfullife.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn(a)virtuozzo.com>
Cc: "Eric W. Biederman" <ebiederm(a)xmission.com>
Cc: Davidlohr Bueso <dave(a)stgolabs.net>
Cc: Greg KH <gregkh(a)linuxfoundation.org>
Cc: Andrei Vagin <avagin(a)gmail.com>
Cc: Pavel Tikhomirov <ptikhomirov(a)virtuozzo.com>
Cc: Vasily Averin <vvs(a)virtuozzo.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 05e22770af51..b75395ec8d52 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -131,6 +131,16 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
return ns;
}
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+ if (ns) {
+ if (refcount_inc_not_zero(&ns->ns.count))
+ return ns;
+ }
+
+ return NULL;
+}
+
extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
@@ -147,6 +157,11 @@ static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
return ns;
}
+static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
+{
+ return ns;
+}
+
static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index ba88a6987400..058d7f371e25 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -158,7 +158,7 @@ static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
* Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
* subscriptions and synchronises with wait4(). Also used in procfs. Also
* pins the final release of task.io_context. Also protects ->cpuset and
- * ->cgroup.subsys[]. And ->vfork_done.
+ * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist.
*
* Nests both inside and outside of read_lock(&tasklist_lock).
* It must not be nested with write_lock_irq(&tasklist_lock),
diff --git a/ipc/shm.c b/ipc/shm.c
index 4942bdd65748..b3048ebd5c31 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -62,9 +62,18 @@ struct shmid_kernel /* private to the kernel */
struct pid *shm_lprid;
struct ucounts *mlock_ucounts;
- /* The task created the shm object. NULL if the task is dead. */
+ /*
+ * The task created the shm object, for
+ * task_lock(shp->shm_creator)
+ */
struct task_struct *shm_creator;
- struct list_head shm_clist; /* list by creator */
+
+ /*
+ * List by creator. task_lock(->shm_creator) required for read/write.
+ * If list_empty(), then the creator is dead already.
+ */
+ struct list_head shm_clist;
+ struct ipc_namespace *ns;
} __randomize_layout;
/* shm_mode upper byte flags */
@@ -115,6 +124,7 @@ static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
struct shmid_kernel *shp;
shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ WARN_ON(ns != shp->ns);
if (shp->shm_nattch) {
shp->shm_perm.mode |= SHM_DEST;
@@ -225,10 +235,43 @@ static void shm_rcu_free(struct rcu_head *head)
kfree(shp);
}
-static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
+/*
+ * It has to be called with shp locked.
+ * It must be called before ipc_rmid()
+ */
+static inline void shm_clist_rm(struct shmid_kernel *shp)
{
- list_del(&s->shm_clist);
- ipc_rmid(&shm_ids(ns), &s->shm_perm);
+ struct task_struct *creator;
+
+ /* ensure that shm_creator does not disappear */
+ rcu_read_lock();
+
+ /*
+ * A concurrent exit_shm may do a list_del_init() as well.
+ * Just do nothing if exit_shm already did the work
+ */
+ if (!list_empty(&shp->shm_clist)) {
+ /*
+ * shp->shm_creator is guaranteed to be valid *only*
+ * if shp->shm_clist is not empty.
+ */
+ creator = shp->shm_creator;
+
+ task_lock(creator);
+ /*
+ * list_del_init() is a nop if the entry was already removed
+ * from the list.
+ */
+ list_del_init(&shp->shm_clist);
+ task_unlock(creator);
+ }
+ rcu_read_unlock();
+}
+
+static inline void shm_rmid(struct shmid_kernel *s)
+{
+ shm_clist_rm(s);
+ ipc_rmid(&shm_ids(s->ns), &s->shm_perm);
}
@@ -283,7 +326,7 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
shm_file = shp->shm_file;
shp->shm_file = NULL;
ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
- shm_rmid(ns, shp);
+ shm_rmid(shp);
shm_unlock(shp);
if (!is_file_hugepages(shm_file))
shmem_lock(shm_file, 0, shp->mlock_ucounts);
@@ -303,10 +346,10 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
*
* 2) sysctl kernel.shm_rmid_forced is set to 1.
*/
-static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
+static bool shm_may_destroy(struct shmid_kernel *shp)
{
return (shp->shm_nattch == 0) &&
- (ns->shm_rmid_forced ||
+ (shp->ns->shm_rmid_forced ||
(shp->shm_perm.mode & SHM_DEST));
}
@@ -337,7 +380,7 @@ static void shm_close(struct vm_area_struct *vma)
ipc_update_pid(&shp->shm_lprid, task_tgid(current));
shp->shm_dtim = ktime_get_real_seconds();
shp->shm_nattch--;
- if (shm_may_destroy(ns, shp))
+ if (shm_may_destroy(shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);
@@ -358,10 +401,10 @@ static int shm_try_destroy_orphaned(int id, void *p, void *data)
*
* As shp->* are changed under rwsem, it's safe to skip shp locking.
*/
- if (shp->shm_creator != NULL)
+ if (!list_empty(&shp->shm_clist))
return 0;
- if (shm_may_destroy(ns, shp)) {
+ if (shm_may_destroy(shp)) {
shm_lock_by_ptr(shp);
shm_destroy(ns, shp);
}
@@ -379,48 +422,97 @@ void shm_destroy_orphaned(struct ipc_namespace *ns)
/* Locking assumes this will only be called with task == current */
void exit_shm(struct task_struct *task)
{
- struct ipc_namespace *ns = task->nsproxy->ipc_ns;
- struct shmid_kernel *shp, *n;
+ for (;;) {
+ struct shmid_kernel *shp;
+ struct ipc_namespace *ns;
- if (list_empty(&task->sysvshm.shm_clist))
- return;
+ task_lock(task);
+
+ if (list_empty(&task->sysvshm.shm_clist)) {
+ task_unlock(task);
+ break;
+ }
+
+ shp = list_first_entry(&task->sysvshm.shm_clist, struct shmid_kernel,
+ shm_clist);
- /*
- * If kernel.shm_rmid_forced is not set then only keep track of
- * which shmids are orphaned, so that a later set of the sysctl
- * can clean them up.
- */
- if (!ns->shm_rmid_forced) {
- down_read(&shm_ids(ns).rwsem);
- list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
- shp->shm_creator = NULL;
/*
- * Only under read lock but we are only called on current
- * so no entry on the list will be shared.
+ * 1) Get pointer to the ipc namespace. It is worth to say
+ * that this pointer is guaranteed to be valid because
+ * shp lifetime is always shorter than namespace lifetime
+ * in which shp lives.
+ * We taken task_lock it means that shp won't be freed.
*/
- list_del(&task->sysvshm.shm_clist);
- up_read(&shm_ids(ns).rwsem);
- return;
- }
+ ns = shp->ns;
- /*
- * Destroy all already created segments, that were not yet mapped,
- * and mark any mapped as orphan to cover the sysctl toggling.
- * Destroy is skipped if shm_may_destroy() returns false.
- */
- down_write(&shm_ids(ns).rwsem);
- list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
- shp->shm_creator = NULL;
+ /*
+ * 2) If kernel.shm_rmid_forced is not set then only keep track of
+ * which shmids are orphaned, so that a later set of the sysctl
+ * can clean them up.
+ */
+ if (!ns->shm_rmid_forced)
+ goto unlink_continue;
- if (shm_may_destroy(ns, shp)) {
- shm_lock_by_ptr(shp);
- shm_destroy(ns, shp);
+ /*
+ * 3) get a reference to the namespace.
+ * The refcount could be already 0. If it is 0, then
+ * the shm objects will be free by free_ipc_work().
+ */
+ ns = get_ipc_ns_not_zero(ns);
+ if (!ns) {
+unlink_continue:
+ list_del_init(&shp->shm_clist);
+ task_unlock(task);
+ continue;
}
- }
- /* Remove the list head from any segments still attached. */
- list_del(&task->sysvshm.shm_clist);
- up_write(&shm_ids(ns).rwsem);
+ /*
+ * 4) get a reference to shp.
+ * This cannot fail: shm_clist_rm() is called before
+ * ipc_rmid(), thus the refcount cannot be 0.
+ */
+ WARN_ON(!ipc_rcu_getref(&shp->shm_perm));
+
+ /*
+ * 5) unlink the shm segment from the list of segments
+ * created by current.
+ * This must be done last. After unlinking,
+ * only the refcounts obtained above prevent IPC_RMID
+ * from destroying the segment or the namespace.
+ */
+ list_del_init(&shp->shm_clist);
+
+ task_unlock(task);
+
+ /*
+ * 6) we have all references
+ * Thus lock & if needed destroy shp.
+ */
+ down_write(&shm_ids(ns).rwsem);
+ shm_lock_by_ptr(shp);
+ /*
+ * rcu_read_lock was implicitly taken in shm_lock_by_ptr, it's
+ * safe to call ipc_rcu_putref here
+ */
+ ipc_rcu_putref(&shp->shm_perm, shm_rcu_free);
+
+ if (ipc_valid_object(&shp->shm_perm)) {
+ if (shm_may_destroy(shp))
+ shm_destroy(ns, shp);
+ else
+ shm_unlock(shp);
+ } else {
+ /*
+ * Someone else deleted the shp from namespace
+ * idr/kht while we have waited.
+ * Just unlock and continue.
+ */
+ shm_unlock(shp);
+ }
+
+ up_write(&shm_ids(ns).rwsem);
+ put_ipc_ns(ns); /* paired with get_ipc_ns_not_zero */
+ }
}
static vm_fault_t shm_fault(struct vm_fault *vmf)
@@ -676,7 +768,11 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
if (error < 0)
goto no_id;
+ shp->ns = ns;
+
+ task_lock(current);
list_add(&shp->shm_clist, ¤t->sysvshm.shm_clist);
+ task_unlock(current);
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
@@ -1567,7 +1663,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
down_write(&shm_ids(ns).rwsem);
shp = shm_lock(ns, shmid);
shp->shm_nattch--;
- if (shm_may_destroy(ns, shp))
+
+ if (shm_may_destroy(shp))
shm_destroy(ns, shp);
else
shm_unlock(shp);