kernel/linux.git/security/keys/keyring.c, branch v7.2-rc6

keys: make keyring key-chunk byte order agree with keyring_diff_objects()

2026-07-23T15:23:39+00:00

keyring_get_key_chunk() loads description bytes into the index chunk low address first, while keyring_diff_objects() numbers the first differing bit from the low end and folds the absolute byte index into the level without removing the inline-prefix offset the level already carries. The two disagree on byte order and bit position, so the array can be told two keys first differ at a bit that does not differ in the chunk the walker uses, letting crafted descriptions collide into one node. Load the chunk in the order keyring_diff_objects() assumes and drop the inline-prefix length when folding the byte index into the level. This only changes the in-memory ordering used to place keys within a keyring; add, search and read of non-colliding keys are unaffected. Fixes: f771fde82051 ("keys: Simplify key description management") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20260719161505.2423935-3-michael.bommarito@gmail.com Signed-off-by: Jarkko Sakkinen

keys: fix out-of-bounds read in keyring_get_key_chunk()

2026-07-23T15:23:32+00:00

For description-level chunks keyring_get_key_chunk() advances the read pointer by level * sizeof(long) past the inline prefix but only bounds-checks the prefix, so a long enough key description is read past its kmemdup(desc, desc_len + 1) allocation. Compute the full byte offset and bounds-check the description against it before reading. The walk only reaches a description-level chunk when two keys collide through the hash, x, type and domain_tag chunks, so this is reached from an unprivileged add_key(2) with a crafted pair of same-type keys whose index hashes collide; KASAN reports a slab-out-of-bounds read. Fixes: f771fde82051 ("keys: Simplify key description management") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20260719161505.2423935-2-michael.bommarito@gmail.com Signed-off-by: Jarkko Sakkinen

KEYS: Use acquire when reading state in keyring search

2026-06-15T12:19:12+00:00

The negative-key race fix added release/acquire ordering for key use. Publish payload before state; read state before payload. keyring_search_iterator() still uses READ_ONCE() before match callbacks. An asymmetric match callback calls asymmetric_key_ids(), which reads key->payload.data[asym_key_ids]. Use key_read_state() there to complete that ordering. Fixes: 363b02dab09b ("KEYS: Fix race between updating and finding a negative key") Signed-off-by: Gui-Dong Han Reviewed-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20260529033406.20673-1-hanguidong02@gmail.com Signed-off-by: Jarkko Sakkinen

security/keys: fix missed RCU read section on lookup

2026-05-28T18:45:41+00:00

Nicholas Carlini reports that the keyring code calls assoc_array_find() in find_key_to_update() without holding the RCU read lock, while the assoc_array_gc() code really is designed around removing the node from the tree and then freeing it after an RCU grace-period. The regular key handling doesn't see this because holding the keyring semaphore hides any lifetime issues, but the persistent key handling uses a different model. Instead of extending the keyring locking, just do the simple RCU locking that the assoc_array was designed for. Reported-by: Nicholas Carlini Cc: David Howells Cc: Jarkko Sakkinen Cc: Paul Moore Cc: James Morris James Morris Cc: Serge E. Hallyn Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

security/keys: fix slab-out-of-bounds in key_task_permission

2024-11-04T19:24:24+00:00

KASAN reports an out of bounds read: BUG: KASAN: slab-out-of-bounds in __kuid_val include/linux/uidgid.h:36 BUG: KASAN: slab-out-of-bounds in uid_eq include/linux/uidgid.h:63 [inline] BUG: KASAN: slab-out-of-bounds in key_task_permission+0x394/0x410 security/keys/permission.c:54 Read of size 4 at addr ffff88813c3ab618 by task stress-ng/4362 CPU: 2 PID: 4362 Comm: stress-ng Not tainted 5.10.0-14930-gafbffd6c3ede #15 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:123 print_address_description.constprop.0+0x19/0x170 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 __kuid_val include/linux/uidgid.h:36 [inline] uid_eq include/linux/uidgid.h:63 [inline] key_task_permission+0x394/0x410 security/keys/permission.c:54 search_nested_keyrings+0x90e/0xe90 security/keys/keyring.c:793 This issue was also reported by syzbot. It can be reproduced by following these steps(more details [1]): 1. Obtain more than 32 inputs that have similar hashes, which ends with the pattern '0xxxxxxxe6'. 2. Reboot and add the keys obtained in step 1. The reproducer demonstrates how this issue happened: 1. In the search_nested_keyrings function, when it iterates through the slots in a node(below tag ascend_to_node), if the slot pointer is meta and node->back_pointer != NULL(it means a root), it will proceed to descend_to_node. However, there is an exception. If node is the root, and one of the slots points to a shortcut, it will be treated as a keyring. 2. Whether the ptr is keyring decided by keyring_ptr_is_keyring function. However, KEYRING_PTR_SUBTYPE is 0x2UL, the same as ASSOC_ARRAY_PTR_SUBTYPE_MASK. 3. When 32 keys with the similar hashes are added to the tree, the ROOT has keys with hashes that are not similar (e.g. slot 0) and it splits NODE A without using a shortcut. When NODE A is filled with keys that all hashes are xxe6, the keys are similar, NODE A will split with a shortcut. Finally, it forms the tree as shown below, where slot 6 points to a shortcut. NODE A +------>+---+ ROOT | | 0 | xxe6 +---+ | +---+ xxxx | 0 | shortcut : : xxe6 +---+ | +---+ xxe6 : : | | | xxe6 +---+ | +---+ | 6 |---+ : : xxe6 +---+ +---+ xxe6 : : | f | xxe6 +---+ +---+ xxe6 | f | +---+ 4. As mentioned above, If a slot(slot 6) of the root points to a shortcut, it may be mistakenly transferred to a key*, leading to a read out-of-bounds read. To fix this issue, one should jump to descend_to_node if the ptr is a shortcut, regardless of whether the node is root or not. [1] https://lore.kernel.org/linux-kernel/1cfa878e-8c7b-4570-8606-21daf5e13ce7@huaweicloud.com/ [jarkko: tweaked the commit message a bit to have an appropriate closes tag.] Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Reported-by: syzbot+5b415c07907a2990d1a3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000cbb7860611f61147@google.com/T/ Signed-off-by: Chen Ridong Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen

security/keys: Remove inconsistent __user annotation

2022-10-04T21:25:56+00:00

The declaration of keyring_read does not match the definition (security/keys/keyring.c). In this case the definition is correct because it matches what defined in "struct key_type::read" (linux/key-type.h). Fix the declaration removing the inconsistent __user annotation. Cc: David Howells Cc: Jarkko Sakkinen Cc: Paul Moore Cc: James Morris Signed-off-by: Vincenzo Frascino Reviewed-by: Paul Moore Acked-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen

security: keys: delete repeated words in comments

2021-01-21T16:16:09+00:00

Drop repeated words in comments. {to, will, the} Signed-off-by: Randy Dunlap Signed-off-by: David Howells Reviewed-by: Jarkko Sakkinen Reviewed-by: Ben Boeckel Cc: keyrings@vger.kernel.org Cc: James Morris Cc: "Serge E. Hallyn" Cc: linux-security-module@vger.kernel.org

keys: Remove outdated __user annotations

2021-01-21T16:16:08+00:00

When the semantics of the ->read() handlers were changed such that "buffer" is a kernel pointer, some __user annotations survived. Since they're wrong now, get rid of them. Fixes: d3ec10aa9581 ("KEYS: Don't write out to userspace while holding key semaphore") Signed-off-by: Jann Horn Signed-off-by: David Howells Reviewed-by: Ben Boeckel