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author | Ingo Molnar <mingo@kernel.org> | 2019-11-25 15:43:15 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2019-11-25 15:43:15 +0100 |
commit | 83bae01182ea755280adc1c3a24032d63a614ede (patch) | |
tree | f05249057a392e750c0622bbdd3620e19aafd031 /kernel/fork.c | |
parent | cf25e24db61cc9df42c47485a2ec2bff4e9a3692 (diff) | |
parent | 7b8474466ed97be458c825f34a85f2c2b84c3f95 (diff) | |
download | linux-stable-83bae01182ea755280adc1c3a24032d63a614ede.tar.gz linux-stable-83bae01182ea755280adc1c3a24032d63a614ede.tar.bz2 linux-stable-83bae01182ea755280adc1c3a24032d63a614ede.zip |
Merge branch 'timers/urgent' into timers/core, to pick up fix
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r-- | kernel/fork.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 1392ee8f4848..7e3a8e1b773a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2561,7 +2561,35 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs, return 0; } -static bool clone3_args_valid(const struct kernel_clone_args *kargs) +/** + * clone3_stack_valid - check and prepare stack + * @kargs: kernel clone args + * + * Verify that the stack arguments userspace gave us are sane. + * In addition, set the stack direction for userspace since it's easy for us to + * determine. + */ +static inline bool clone3_stack_valid(struct kernel_clone_args *kargs) +{ + if (kargs->stack == 0) { + if (kargs->stack_size > 0) + return false; + } else { + if (kargs->stack_size == 0) + return false; + + if (!access_ok((void __user *)kargs->stack, kargs->stack_size)) + return false; + +#if !defined(CONFIG_STACK_GROWSUP) && !defined(CONFIG_IA64) + kargs->stack += kargs->stack_size; +#endif + } + + return true; +} + +static bool clone3_args_valid(struct kernel_clone_args *kargs) { /* * All lower bits of the flag word are taken. @@ -2581,6 +2609,9 @@ static bool clone3_args_valid(const struct kernel_clone_args *kargs) kargs->exit_signal) return false; + if (!clone3_stack_valid(kargs)) + return false; + return true; } |