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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2023-01-09 20:28:19 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2023-01-09 20:28:19 -0800 |
| commit | 407da561244b9d51e6a794d6305ba38ec2c9d907 (patch) | |
| tree | a9b8e399f85eb14f9591fc654ae2372281ffa729 /include/linux/stackprotector.h | |
| parent | 144ff5e03d745a299a9aabe2a597da843cf1c430 (diff) | |
| parent | b7bfaa761d760e72a969d116517eaa12e404c262 (diff) | |
Merge tag 'v6.2-rc3' into next
Merge with mainline to bring in timer_shutdown_sync() API.
Diffstat (limited to 'include/linux/stackprotector.h')
| -rw-r--r-- | include/linux/stackprotector.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h index 4c678c4fec58..9c88707d9a0f 100644 --- a/include/linux/stackprotector.h +++ b/include/linux/stackprotector.h @@ -6,6 +6,25 @@ #include <linux/sched.h> #include <linux/random.h> +/* + * On 64-bit architectures, protect against non-terminated C string overflows + * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. + */ +#ifdef CONFIG_64BIT +# ifdef __LITTLE_ENDIAN +# define CANARY_MASK 0xffffffffffffff00UL +# else /* big endian, 64 bits: */ +# define CANARY_MASK 0x00ffffffffffffffUL +# endif +#else /* 32 bits: */ +# define CANARY_MASK 0xffffffffUL +#endif + +static inline unsigned long get_random_canary(void) +{ + return get_random_long() & CANARY_MASK; +} + #if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH) # include <asm/stackprotector.h> #else |