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 --- crypto/lzo.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 crypto/lzo.c (limited to 'crypto/lzo.c') diff --git a/crypto/lzo.c b/crypto/lzo.c new file mode 100644 index 000000000..d43242b24 --- /dev/null +++ b/crypto/lzo.c @@ -0,0 +1,101 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Cryptographic API. + */ + +#include +#include +#include +#include +#include + +static void *lzo_alloc_ctx(void) +{ + void *ctx; + + ctx = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!ctx) + return ERR_PTR(-ENOMEM); + + return ctx; +} + +static void lzo_free_ctx(void *ctx) +{ + kvfree(ctx); +} + +static int __lzo_compress(const u8 *src, unsigned int slen, + u8 *dst, unsigned int *dlen, void *ctx) +{ + size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ + int err; + + err = lzo1x_1_compress_safe(src, slen, dst, &tmp_len, ctx); + + if (err != LZO_E_OK) + return -EINVAL; + + *dlen = tmp_len; + return 0; +} + +static int lzo_scompress(struct crypto_scomp *tfm, const u8 *src, + unsigned int slen, u8 *dst, unsigned int *dlen, + void *ctx) +{ + return __lzo_compress(src, slen, dst, dlen, ctx); +} + +static int __lzo_decompress(const u8 *src, unsigned int slen, + u8 *dst, unsigned int *dlen) +{ + int err; + size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */ + + err = lzo1x_decompress_safe(src, slen, dst, &tmp_len); + + if (err != LZO_E_OK) + return -EINVAL; + + *dlen = tmp_len; + return 0; +} + +static int lzo_sdecompress(struct crypto_scomp *tfm, const u8 *src, + unsigned int slen, u8 *dst, unsigned int *dlen, + void *ctx) +{ + return __lzo_decompress(src, slen, dst, dlen); +} + +static struct scomp_alg scomp = { + .streams = { + .alloc_ctx = lzo_alloc_ctx, + .free_ctx = lzo_free_ctx, + }, + .compress = lzo_scompress, + .decompress = lzo_sdecompress, + .base = { + .cra_name = "lzo", + .cra_driver_name = "lzo-scomp", + .cra_module = THIS_MODULE, + } +}; + +static int __init lzo_mod_init(void) +{ + return crypto_register_scomp(&scomp); +} + +static void __exit lzo_mod_fini(void) +{ + crypto_unregister_scomp(&scomp); +} + +module_init(lzo_mod_init); +module_exit(lzo_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("LZO Compression Algorithm"); +MODULE_ALIAS_CRYPTO("lzo"); -- cgit v1.3.1