kernel/linux.git/ipc, branch v6.12.80

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

2026-03-04T12:20:07+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

2025-06-27T10:11:22+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

2024-12-05T13:03:02+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

Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2024-09-23T16:35:36+00:00

Pull 'struct fd' updates from Al Viro: "Just the 'struct fd' layout change, with conversion to accessor helpers" * tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: add struct fd constructors, get rid of __to_fd() struct fd: representation change introduce fd_file(), convert all accessors to it.

ipc/shm, mm: drop do_vma_munmap()

2024-09-04T04:15:52+00:00

The do_vma_munmap() wrapper existed for callers that didn't have a vma iterator and needed to check the vma mseal status prior to calling the underlying munmap(). All callers now use a vma iterator and since the mseal check has been moved to do_vmi_align_munmap() and the vmas are aligned, this function can just be called instead. do_vmi_align_munmap() can no longer be static as ipc/shm is using it and it is exported via the mm.h header. Link: https://lkml.kernel.org/r/20240830040101.822209-19-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Reviewed-by: Lorenzo Stoakes Cc: Bert Karwatzki Cc: Jeff Xu Cc: Jiri Olsa Cc: Kees Cook Cc: Lorenzo Stoakes Cc: Mark Brown Cc: Matthew Wilcox Cc: "Paul E. McKenney" Cc: Paul Moore Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

introduce fd_file(), convert all accessors to it.

2024-08-13T02:00:43+00:00

For any changes of struct fd representation we need to turn existing accesses to fields into calls of wrappers. Accesses to struct fd::flags are very few (3 in linux/file.h, 1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in explicit initializers). Those can be dealt with in the commit converting to new layout; accesses to struct fd::file are too many for that. This commit converts (almost) all of f.file to fd_file(f). It's not entirely mechanical ('file' is used as a member name more than just in struct fd) and it does not even attempt to distinguish the uses in pointer context from those in boolean context; the latter will be eventually turned into a separate helper (fd_empty()). NOTE: mass conversion to fd_empty(), tempting as it might be, is a bad idea; better do that piecewise in commit that convert from fdget...() to CLASS(...). [conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c caught by git; fs/stat.c one got caught by git grep] [fs/xattr.c conflict] Reviewed-by: Christian Brauner Signed-off-by: Al Viro

sysctl: treewide: constify the ctl_table argument of proc_handlers

2024-07-24T18:59:29+00:00

const qualify the struct ctl_table argument in the proc_handler function signatures. This is a prerequisite to moving the static ctl_table structs into .rodata data which will ensure that proc_handler function pointers cannot be modified. This patch has been generated by the following coccinelle script: ``` virtual patch @r1@ identifier ctl, write, buffer, lenp, ppos; identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)"; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos); @r2@ identifier func, ctl, write, buffer, lenp, ppos; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos) { ... } @r3@ identifier func; @@ int func( - struct ctl_table * + const struct ctl_table * ,int , void *, size_t *, loff_t *); @r4@ identifier func, ctl; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int , void *, size_t *, loff_t *); @r5@ identifier func, write, buffer, lenp, ppos; @@ int func( - struct ctl_table * + const struct ctl_table * ,int write, void *buffer, size_t *lenp, loff_t *ppos); ``` * Code formatting was adjusted in xfs_sysctl.c to comply with code conventions. The xfs_stats_clear_proc_handler, xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where adjusted. * The ctl_table argument in proc_watchdog_common was const qualified. This is called from a proc_handler itself and is calling back into another proc_handler, making it necessary to change it as part of the proc_handler migration. Co-developed-by: Thomas Weißschuh Signed-off-by: Thomas Weißschuh Co-developed-by: Joel Granados Signed-off-by: Joel Granados

Merge tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2024-07-18T22:08:12+00:00

Pull slab updates from Vlastimil Babka: "The most prominent change this time is the kmem_buckets based hardening of kmalloc() allocations from Kees Cook. We have also extended the kmalloc() alignment guarantees for non-power-of-two sizes in a way that benefits rust. The rest are various cleanups and non-critical fixups. - Dedicated bucket allocator (Kees Cook) This series [1] enhances the probabilistic defense against heap spraying/grooming of CONFIG_RANDOM_KMALLOC_CACHES from last year. kmalloc() users that are known to be useful for exploits can get completely separate set of kmalloc caches that can't be shared with other users. The first converted users are alloc_msg() and memdup_user(). The hardening is enabled by CONFIG_SLAB_BUCKETS. - Extended kmalloc() alignment guarantees (Vlastimil Babka) For years now we have guaranteed natural alignment for power-of-two allocations, but nothing was defined for other sizes (in practice, we have two such buckets, kmalloc-96 and kmalloc-192). To avoid unnecessary padding in the rust layer due to its alignment rules, extend the guarantee so that the alignment is at least the largest power-of-two divisor of the requested size. This fits what rust needs, is a superset of the existing power-of-two guarantee, and does not in practice change the layout (and thus does not add overhead due to padding) of the kmalloc-96 and kmalloc-192 caches, unless slab debugging is enabled for them. - Cleanups and non-critical fixups (Chengming Zhou, Suren Baghdasaryan, Matthew Willcox, Alex Shi, and Vlastimil Babka) Various tweaks related to the new alloc profiling code, folio conversion, debugging and more leftovers after SLAB" Link: https://lore.kernel.org/all/20240701190152.it.631-kees@kernel.org/ [1] * tag 'slab-for-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/memcg: alignment memcg_data define condition mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING mm, slab: move allocation tagging code in the alloc path into a hook mm/util: Use dedicated slab buckets for memdup_user() ipc, msg: Use dedicated slab buckets for alloc_msg() mm/slab: Introduce kmem_buckets_create() and family mm/slab: Introduce kvmalloc_buckets_node() that can take kmem_buckets argument mm/slab: Plumb kmem_buckets into __do_kmalloc_node() mm/slab: Introduce kmem_buckets typedef slab, rust: extend kmalloc() alignment guarantees to remove Rust padding slab: delete useless RED_INACTIVE and RED_ACTIVE slab: don't put freepointer outside of object if only orig_size slab: make check_object() more consistent mm: Reduce the number of slab->folio casts mm, slab: don't wrap internal functions with alloc_hooks()

ipc: mqueue: remove assignment from IS_ERR argument

2024-07-09T04:47:40+00:00

Remove assignment from IS_ERR() argument. This is detected by coccinelle. Signed-off-by: Chen Ni Link: https://lore.kernel.org/r/20240708080404.3859094-1-nichen@iscas.ac.cn Signed-off-by: Christian Brauner

ipc, msg: Use dedicated slab buckets for alloc_msg()

2024-07-03T10:24:20+00:00

The msg subsystem is a common target for exploiting[1][2][3][4][5][6][7] use-after-free type confusion flaws in the kernel for both read and write primitives. Avoid having a user-controlled dynamically-size allocation share the global kmalloc cache by using a separate set of kmalloc buckets via the kmem_buckets API. Link: https://blog.hacktivesecurity.com/index.php/2022/06/13/linux-kernel-exploit-development-1day-case-study/ [1] Link: https://hardenedvault.net/blog/2022-11-13-msg_msg-recon-mitigation-ved/ [2] Link: https://www.willsroot.io/2021/08/corctf-2021-fire-of-salvation-writeup.html [3] Link: https://a13xp0p0v.github.io/2021/02/09/CVE-2021-26708.html [4] Link: https://google.github.io/security-research/pocs/linux/cve-2021-22555/writeup.html [5] Link: https://zplin.me/papers/ELOISE.pdf [6] Link: https://syst3mfailure.io/wall-of-perdition/ [7] Signed-off-by: Kees Cook Signed-off-by: Vlastimil Babka