kernel/linux.git/ipc, branch v6.6.132

ipc: don't audit capability check in ipc_permissions()

2026-03-04T12:19:49+00:00

[ Upstream commit 071588136007482d70fd2667b827036bc60b1f8f ] The IPC sysctls implement the ctl_table_root::permissions hook and they override the file access mode based on the CAP_CHECKPOINT_RESTORE capability, which is being checked regardless of whether any access is actually denied or not, so if an LSM denies the capability, an audit record may be logged even when access is in fact granted. It wouldn't be viable to restructure the sysctl permission logic to only check the capability when the access would be actually denied if it's not granted. Thus, do the same as in net_ctl_permissions() (net/sysctl_net.c) - switch from ns_capable() to ns_capable_noaudit(), so that the check never emits an audit record. Fixes: 0889f44e2810 ("ipc: Check permissions for checkpoint_restart sysctls at open time") Signed-off-by: Ondrej Mosnacek Acked-by: Alexey Gladkov Acked-by: Serge Hallyn Signed-off-by: Serge Hallyn Stable-dep-of: 8924336531e2 ("ipc: don't audit capability check in ipc_permissions()") Signed-off-by: Sasha Levin

ipc: fix to protect IPCS lookups using RCU

2025-06-27T10:08:49+00:00

commit d66adabe91803ef34a8b90613c81267b5ded1472 upstream. syzbot reported that it discovered a use-after-free vulnerability, [0] [0]: https://lore.kernel.org/all/67af13f8.050a0220.21dd3.0038.GAE@google.com/ idr_for_each() is protected by rwsem, but this is not enough. If it is not protected by RCU read-critical region, when idr_for_each() calls radix_tree_node_free() through call_rcu() to free the radix_tree_node structure, the node will be freed immediately, and when reading the next node in radix_tree_for_each_slot(), the already freed memory may be read. Therefore, we need to add code to make sure that idr_for_each() is protected within the RCU read-critical region when we call it in shm_destroy_orphaned(). Link: https://lkml.kernel.org/r/20250424143322.18830-1-aha310510@gmail.com Fixes: b34a6b1da371 ("ipc: introduce shm_rmid_forced sysctl") Signed-off-by: Jeongjun Park Reported-by: syzbot+a2b84e569d06ca3a949c@syzkaller.appspotmail.com Cc: Jeongjun Park Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Vasiliy Kulikov Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

ipc: fix memleak if msg_init_ns failed in create_ipc_ns

2024-12-09T09:32:54+00:00

commit bc8f5921cd69188627c08041276238de222ab466 upstream. Percpu memory allocation may failed during create_ipc_ns however this fail is not handled properly since ipc sysctls and mq sysctls is not released properly. Fix this by release these two resource when failure. Here is the kmemleak stack when percpu failed: unreferenced object 0xffff88819de2a600 (size 512): comm "shmem_2nstest", pid 120711, jiffies 4300542254 hex dump (first 32 bytes): 60 aa 9d 84 ff ff ff ff fc 18 48 b2 84 88 ff ff `.........H..... 04 00 00 00 a4 01 00 00 20 e4 56 81 ff ff ff ff ........ .V..... backtrace (crc be7cba35): [] __kmalloc_node_track_caller_noprof+0x333/0x420 [] kmemdup_noprof+0x26/0x50 [] setup_mq_sysctls+0x57/0x1d0 [] copy_ipcs+0x29c/0x3b0 [] create_new_namespaces+0x1d0/0x920 [] copy_namespaces+0x2e9/0x3e0 [] copy_process+0x29f3/0x7ff0 [] kernel_clone+0xc0/0x650 [] __do_sys_clone+0xa1/0xe0 [] do_syscall_64+0xbf/0x1c0 [] entry_SYSCALL_64_after_hwframe+0x4b/0x53 Link: https://lkml.kernel.org/r/20241023093129.3074301-1-mawupeng1@huawei.com Fixes: 72d1e611082e ("ipc/msg: mitigate the lock contention with percpu counter") Signed-off-by: Ma Wupeng Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)

2024-08-11T10:47:13+00:00

[ Upstream commit 520713a93d550406dae14d49cdb8778d70cecdfd ] Remove the 'table' argument from set_ownership as it is never used. This change is a step towards putting "struct ctl_table" into .rodata and eventually having sysctl core only use "const struct ctl_table". The patch was created with the following coccinelle script: @@ identifier func, head, table, uid, gid; @@ void func( struct ctl_table_header *head, - struct ctl_table *table, kuid_t *uid, kgid_t *gid) { ... } No additional occurrences of 'set_ownership' were found after doing a tree-wide search. Reviewed-by: Joel Granados Signed-off-by: Thomas Weißschuh Signed-off-by: Joel Granados Stable-dep-of: 98ca62ba9e2b ("sysctl: always initialize i_uid/i_gid") Signed-off-by: Sasha Levin

sysctl: allow to change limits for posix messages queues

2024-08-11T10:47:12+00:00

[ Upstream commit f9436a5d0497f759330d07e1189565edd4456be8 ] All parameters of posix messages queues (queues_max/msg_max/msgsize_max) end up being limited by RLIMIT_MSGQUEUE. The code in mqueue_get_inode is where that limiting happens. The RLIMIT_MSGQUEUE is bound to the user namespace and is counted hierarchically. We can allow root in the user namespace to modify the posix messages queues parameters. Link: https://lkml.kernel.org/r/6ad67f23d1459a4f4339f74aa73bac0ecf3995e1.1705333426.git.legion@kernel.org Signed-off-by: Alexey Gladkov Signed-off-by: Eric W. Biederman Link: https://lkml.kernel.org/r/7eb21211c8622e91d226e63416b1b93c079f60ee.1663756794.git.legion@kernel.org Cc: Christian Brauner Cc: Davidlohr Bueso Cc: Joel Granados Cc: Kees Cook Cc: Luis Chamberlain Cc: Manfred Spraul Signed-off-by: Andrew Morton Stable-dep-of: 98ca62ba9e2b ("sysctl: always initialize i_uid/i_gid") Signed-off-by: Sasha Levin

sysctl: allow change system v ipc sysctls inside ipc namespace

2024-08-11T10:47:12+00:00

[ Upstream commit 50ec499b9a43e46200c9f7b7d723ab2e4af540b3 ] Patch series "Allow to change ipc/mq sysctls inside ipc namespace", v3. Right now ipc and mq limits count as per ipc namespace, but only real root can change them. By default, the current values of these limits are such that it can only be reduced. Since only root can change the values, it is impossible to reduce these limits in the rootless container. We can allow limit changes within ipc namespace because mq parameters are limited by RLIMIT_MSGQUEUE and ipc parameters are not limited to anything other than cgroups. This patch (of 3): Rootless containers are not allowed to modify kernel IPC parameters. All default limits are set to such high values that in fact there are no limits at all. All limits are not inherited and are initialized to default values when a new ipc_namespace is created. For new ipc_namespace: size_t ipc_ns.shm_ctlmax = SHMMAX; // (ULONG_MAX - (1UL << 24)) size_t ipc_ns.shm_ctlall = SHMALL; // (ULONG_MAX - (1UL << 24)) int ipc_ns.shm_ctlmni = IPCMNI; // (1 << 15) int ipc_ns.shm_rmid_forced = 0; unsigned int ipc_ns.msg_ctlmax = MSGMAX; // 8192 unsigned int ipc_ns.msg_ctlmni = MSGMNI; // 32000 unsigned int ipc_ns.msg_ctlmnb = MSGMNB; // 16384 The shm_tot (total amount of shared pages) has also ceased to be global, it is located in ipc_namespace and is not inherited from anywhere. In such conditions, it cannot be said that these limits limit anything. The real limiter for them is cgroups. If we allow rootless containers to change these parameters, then it can only be reduced. Link: https://lkml.kernel.org/r/cover.1705333426.git.legion@kernel.org Link: https://lkml.kernel.org/r/d2f4603305cbfed58a24755aa61d027314b73a45.1705333426.git.legion@kernel.org Signed-off-by: Alexey Gladkov Signed-off-by: Eric W. Biederman Link: https://lkml.kernel.org/r/e2d84d3ec0172cfff759e6065da84ce0cc2736f8.1663756794.git.legion@kernel.org Cc: Christian Brauner Cc: Joel Granados Cc: Kees Cook Cc: Luis Chamberlain Cc: Manfred Spraul Cc: Davidlohr Bueso Signed-off-by: Andrew Morton Stable-dep-of: 98ca62ba9e2b ("sysctl: always initialize i_uid/i_gid") Signed-off-by: Sasha Levin

Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-08-31T19:20:12+00:00

Pull x86 shadow stack support from Dave Hansen: "This is the long awaited x86 shadow stack support, part of Intel's Control-flow Enforcement Technology (CET). CET consists of two related security features: shadow stacks and indirect branch tracking. This series implements just the shadow stack part of this feature, and just for userspace. The main use case for shadow stack is providing protection against return oriented programming attacks. It works by maintaining a secondary (shadow) stack using a special memory type that has protections against modification. When executing a CALL instruction, the processor pushes the return address to both the normal stack and to the special permission shadow stack. Upon RET, the processor pops the shadow stack copy and compares it to the normal stack copy. For more information, refer to the links below for the earlier versions of this patch set" Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/ Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/ * tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) x86/shstk: Change order of __user in type x86/ibt: Convert IBT selftest to asm x86/shstk: Don't retry vm_munmap() on -EINTR x86/kbuild: Fix Documentation/ reference x86/shstk: Move arch detail comment out of core mm x86/shstk: Add ARCH_SHSTK_STATUS x86/shstk: Add ARCH_SHSTK_UNLOCK x86: Add PTRACE interface for shadow stack selftests/x86: Add shadow stack test x86/cpufeatures: Enable CET CR4 bit for shadow stack x86/shstk: Wire in shadow stack interface x86: Expose thread features in /proc/$PID/status x86/shstk: Support WRSS for userspace x86/shstk: Introduce map_shadow_stack syscall x86/shstk: Check that signal frame is shadow stack mem x86/shstk: Check that SSP is aligned on sigreturn x86/shstk: Handle signals for shadow stack x86/shstk: Introduce routines modifying shstk x86/shstk: Handle thread shadow stack x86/shstk: Add user-mode shadow stack support ...

Merge tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

2023-08-30T00:39:15+00:00

Pull sysctl updates from Luis Chamberlain: "Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and placings sysctls to their own sybsystem or file to help avoid merge conflicts. Matthew Wilcox pointed out though that if we're going to do that we might as well also *save* space while at it and try to remove the extra last sysctl entry added at the end of each array, a sentintel, instead of bloating the kernel by adding a new sentinel with each array moved. Doing that was not so trivial, and has required slowing down the moves of kernel/sysctl.c arrays and measuring the impact on size by each new move. The complex part of the effort to help reduce the size of each sysctl is being done by the patient work of el señor Don Joel Granados. A lot of this is truly painful code refactoring and testing and then trying to measure the savings of each move and removing the sentinels. Although Joel already has code which does most of this work, experience with sysctl moves in the past shows is we need to be careful due to the slew of odd build failures that are possible due to the amount of random Kconfig options sysctls use. To that end Joel's work is split by first addressing the major housekeeping needed to remove the sentinels, which is part of this merge request. The rest of the work to actually remove the sentinels will be done later in future kernel releases. The preliminary math is showing this will all help reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array where we are able to remove each sentinel in the future. That also means there is no more bloating the kernel with the extra ~64 bytes per array moved as no new sentinels are created" * tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: Use ctl_table_size as stopping criteria for list macro sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl vrf: Update to register_net_sysctl_sz networking: Update to register_net_sysctl_sz netfilter: Update to register_net_sysctl_sz ax.25: Update to register_net_sysctl_sz sysctl: Add size to register_net_sysctl function sysctl: Add size arg to __register_sysctl_init sysctl: Add size to register_sysctl sysctl: Add a size arg to __register_sysctl_table sysctl: Add size argument to init_header sysctl: Add ctl_table_size to ctl_table_header sysctl: Use ctl_table_header in list_for_each_table_entry sysctl: Prefer ctl_table_header in proc_sysctl

Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-08-29T21:53:51+00:00

Pull non-MM updates from Andrew Morton: - An extensive rework of kexec and crash Kconfig from Eric DeVolder ("refactor Kconfig to consolidate KEXEC and CRASH options") - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a couple of macros to args.h") - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper commands") - vsprintf inclusion rationalization from Andy Shevchenko ("lib/vsprintf: Rework header inclusions") - Switch the handling of kdump from a udev scheme to in-kernel handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory hot un/plug") - Many singleton patches to various parts of the tree * tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits) document while_each_thread(), change first_tid() to use for_each_thread() drivers/char/mem.c: shrink character device's devlist[] array x86/crash: optimize CPU changes crash: change crash_prepare_elf64_headers() to for_each_possible_cpu() crash: hotplug support for kexec_load() x86/crash: add x86 crash hotplug support crash: memory and CPU hotplug sysfs attributes kexec: exclude elfcorehdr from the segment digest crash: add generic infrastructure for crash hotplug support crash: move a few code bits to setup support of crash hotplug kstrtox: consistently use _tolower() kill do_each_thread() nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse scripts/bloat-o-meter: count weak symbol sizes treewide: drop CONFIG_EMBEDDED lockdep: fix static memory detection even more lib/vsprintf: declare no_hash_pointers in sprintf.h lib/vsprintf: split out sprintf() and friends kernel/fork: stop playing lockless games for exe_file replacement adfs: delete unused "union adfs_dirtail" definition ...

ipc/sem: use flexible array in 'struct sem_undo'

2023-08-18T17:18:51+00:00

Turn 'semadj' in 'struct sem_undo' into a flexible array. The advantages are: - save the size of a pointer when the new undo structure is allocated - avoid some always ugly pointer arithmetic to get the address of semadj - avoid an indirection when the array is accessed While at it, use struct_size() to compute the size of the new undo structure. Link: https://lkml.kernel.org/r/1ba993d443ad7e16ac2b1902adab1f05ebdfa454.1688918791.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET Reviewed-by: Manfred Spraul Reviewed-by: Davidlohr Bueso Cc: Christophe JAILLET Cc: Jann Horn Signed-off-by: Andrew Morton