From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- include/crypto/gcm.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 include/crypto/gcm.h (limited to 'include/crypto/gcm.h') diff --git a/include/crypto/gcm.h b/include/crypto/gcm.h new file mode 100644 index 000000000..1d5f39ff1 --- /dev/null +++ b/include/crypto/gcm.h @@ -0,0 +1,85 @@ +#ifndef _CRYPTO_GCM_H +#define _CRYPTO_GCM_H + +#include + +#include +#include + +#define GCM_AES_IV_SIZE 12 +#define GCM_RFC4106_IV_SIZE 8 +#define GCM_RFC4543_IV_SIZE 8 + +/* + * validate authentication tag for GCM + */ +static inline int crypto_gcm_check_authsize(unsigned int authsize) +{ + switch (authsize) { + case 4: + case 8: + case 12: + case 13: + case 14: + case 15: + case 16: + break; + default: + return -EINVAL; + } + + return 0; +} + +/* + * validate authentication tag for RFC4106 + */ +static inline int crypto_rfc4106_check_authsize(unsigned int authsize) +{ + switch (authsize) { + case 8: + case 12: + case 16: + break; + default: + return -EINVAL; + } + + return 0; +} + +/* + * validate assoclen for RFC4106/RFC4543 + */ +static inline int crypto_ipsec_check_assoclen(unsigned int assoclen) +{ + switch (assoclen) { + case 16: + case 20: + break; + default: + return -EINVAL; + } + + return 0; +} + +struct aesgcm_ctx { + struct ghash_key ghash_key; + struct aes_enckey aes_key; + unsigned int authsize; +}; + +int aesgcm_expandkey(struct aesgcm_ctx *ctx, const u8 *key, + unsigned int keysize, unsigned int authsize); + +void aesgcm_encrypt(const struct aesgcm_ctx *ctx, u8 *dst, const u8 *src, + int crypt_len, const u8 *assoc, int assoc_len, + const u8 iv[GCM_AES_IV_SIZE], u8 *authtag); + +bool __must_check aesgcm_decrypt(const struct aesgcm_ctx *ctx, u8 *dst, + const u8 *src, int crypt_len, const u8 *assoc, + int assoc_len, const u8 iv[GCM_AES_IV_SIZE], + const u8 *authtag); + +#endif -- cgit v1.3.1