Messages in this thread |  | | Subject | Re: [PATCH v2] prctl: fix compat handling for prctl | From | Andy Lutomirski <> | Date | Wed, 18 Apr 2018 21:35:58 -0400 |
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> On Apr 18, 2018, at 9:06 PM, Li Bin <huawei.libin@huawei.com> wrote: > > The member auxv in prctl_mm_map structure which be shared with > userspace is pointer type, but the kernel supporting COMPAT didn't > handle it. This patch fix the compat handling for prctl syscall. > > Signed-off-by: Li Bin <huawei.libin@huawei.com> > --- > kernel/sys.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 42 insertions(+) > > diff --git a/kernel/sys.c b/kernel/sys.c > index ad69218..d4259938 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -1969,6 +1969,26 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map) > } > > #ifdef CONFIG_CHECKPOINT_RESTORE > + > +#ifdef CONFIG_COMPAT > +struct compat_prctl_mm_map { > + __u64 start_code; /* code section bounds */ > + __u64 end_code; > + __u64 start_data; /* data section bounds */ > + __u64 end_data; > + __u64 start_brk; /* heap for brk() syscall */ > + __u64 brk; > + __u64 start_stack; /* stack starts at */ > + __u64 arg_start; /* command line arguments bounds */ > + __u64 arg_end; > + __u64 env_start; /* environment variables bounds */ > + __u64 env_end; > + compat_uptr_t auxv; /* auxiliary vector */ > + __u32 auxv_size; /* vector size */ > + __u32 exe_fd; /* /proc/$pid/exe link file */ > +}; > +#endif > + > static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) > { > struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; > @@ -1986,6 +2006,28 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data > if (data_size != sizeof(prctl_map)) > return -EINVAL; > > +#ifdef CONFIG_COMPAT > + if (in_compat_syscall()) { > + struct compat_prctl_mm_map prctl_map32; > + if (copy_from_user(&prctl_map32, addr, sizeof(prctl_map32))) > + return -EFAULT; > + > + prctl_map.start_code = prctl_map32.start_code; > + prctl_map.end_code = prctl_map32.end_code; > + prctl_map.start_data = prctl_map32.start_data; > + prctl_map.end_data = prctl_map32.end_data; > + prctl_map.start_brk = prctl_map32.start_brk; > + prctl_map.brk = prctl_map32.brk; > + prctl_map.start_stack = prctl_map32.start_stack; > + prctl_map.arg_start = prctl_map32.arg_start; > + prctl_map.arg_end = prctl_map32.arg_end; > + prctl_map.env_start = prctl_map32.env_start; > + prctl_map.env_end = prctl_map32.env_end; > + prctl_map.auxv = compat_ptr(prctl_map32.auxv); > + prctl_map.auxv_size = prctl_map32.auxv_size; > + prctl_map.exe_fd = prctl_map32.exe_fd; > + } else > +#endif > if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) > return -EFAULT; > > -- > 1.7.12.4 >
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