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| author | Kees Cook <kees@kernel.org> | 2024-07-01 21:13:02 +0200 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2024-07-03 12:24:20 +0200 |
| commit | 734bbc1c97ea7e46e0e53b087de16c87c03bd65f (patch) | |
| tree | a7c5cf2fb6c0215cfe298b79c26fecae47610a27 /ipc | |
| parent | mm/slab: Introduce kmem_buckets_create() and family (diff) | |
| download | linux-734bbc1c97ea7e46e0e53b087de16c87c03bd65f.tar.xz linux-734bbc1c97ea7e46e0e53b087de16c87c03bd65f.zip | |
ipc, msg: Use dedicated slab buckets for alloc_msg()
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 <kees@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/msgutil.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/ipc/msgutil.c b/ipc/msgutil.c index d0a0e877cadd..c7be0c792647 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -42,6 +42,17 @@ struct msg_msgseg { #define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg)) #define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg)) +static kmem_buckets *msg_buckets __ro_after_init; + +static int __init init_msg_buckets(void) +{ + msg_buckets = kmem_buckets_create("msg_msg", SLAB_ACCOUNT, + sizeof(struct msg_msg), + DATALEN_MSG, NULL); + + return 0; +} +subsys_initcall(init_msg_buckets); static struct msg_msg *alloc_msg(size_t len) { @@ -50,7 +61,7 @@ static struct msg_msg *alloc_msg(size_t len) size_t alen; alen = min(len, DATALEN_MSG); - msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL_ACCOUNT); + msg = kmem_buckets_alloc(msg_buckets, sizeof(*msg) + alen, GFP_KERNEL); if (msg == NULL) return NULL; |