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authorH. Peter Anvin <hpa@linux.intel.com>2010-09-07 16:16:18 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-09-20 13:17:57 -0700
commit337b16213b3810a982e34f4b9497745c700da8a0 (patch)
treec411754cab0e44622d6226a9712799029fe9a079 /include
parent7764ec137f93bb83dd287d14ad457325072aa00d (diff)
compat: Make compat_alloc_user_space() incorporate the access_ok()
commit c41d68a513c71e35a14f66d71782d27a79a81ea6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
-rw-r--r--include/linux/compat.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h
index af931ee43dd8..cab23f2da4dc 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -309,5 +309,7 @@ asmlinkage long compat_sys_newfstatat(unsigned int dfd, char __user * filename,
asmlinkage long compat_sys_openat(unsigned int dfd, const char __user *filename,
int flags, int mode);
+extern void __user *compat_alloc_user_space(unsigned long len);
+
#endif /* CONFIG_COMPAT */
#endif /* _LINUX_COMPAT_H */