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authorH. Peter Anvin <hpa@linux.intel.com>2010-09-08 03:16:18 +0400
committerH. Peter Anvin <hpa@linux.intel.com>2010-09-15 03:08:45 +0400
commitc41d68a513c71e35a14f66d71782d27a79a81ea6 (patch)
tree2729377678b4f0fa516404eec6c3a87a4fd7c823 /include
parentbfa88ea7ee9e6b4fd673e45a8cc0a8e0b7ef4761 (diff)
downloadlinux-c41d68a513c71e35a14f66d71782d27a79a81ea6.tar.xz
compat: Make compat_alloc_user_space() incorporate the access_ok()
compat_alloc_user_space() expects the caller to independently call access_ok() to verify the returned area. A missing call could introduce problems on some architectures. This patch incorporates the access_ok() check into compat_alloc_user_space() and also adds a sanity check on the length. The existing compat_alloc_user_space() implementations are renamed arch_compat_alloc_user_space() and are used as part of the implementation of the new global function. This patch assumes NULL will cause __get_user()/__put_user() to either fail or access userspace on all architectures. This should be followed by checking the return value of compat_access_user_space() for NULL in the callers, at which time the access_ok() in the callers can also be removed. Reported-by: Ben Hawkes <hawkes@sota.gen.nz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <jejb@parisc-linux.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: <stable@kernel.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/compat.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9ddc8780e8db..5778b559d59c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -360,5 +360,8 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
const struct compat_iovec __user *uvector, unsigned long nr_segs,
unsigned long fast_segs, struct iovec *fast_pointer,
struct iovec **ret_pointer);
+
+extern void __user *compat_alloc_user_space(unsigned long len);
+
#endif /* CONFIG_COMPAT */
#endif /* _LINUX_COMPAT_H */