[PATCH 3.11 194/233] fs/compat: fix lookup_dcookie() parameter handling

From: Luis Henriques
Date: Fri Feb 07 2014 - 07:01:00 EST


3.11.10.4 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

commit d8d14bd09cddbaf0168d61af638455a26bd027ff upstream.

Commit d5dc77bfeeab ("consolidate compat lookup_dcookie()") coverted all
architectures to the new compat_sys_lookup_dcookie() syscall.

The "len" paramater of the new compat syscall must have the type
compat_size_t in order to enforce zero extension for architectures where
the ABI requires that the caller of a function performed zero and/or
sign extension to 64 bit of all parameters.

Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
fs/dcookies.c | 2 +-
include/linux/compat.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/dcookies.c b/fs/dcookies.c
index ab5954b..ac44a69 100644
--- a/fs/dcookies.c
+++ b/fs/dcookies.c
@@ -204,7 +204,7 @@ out:
}

#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, size_t, len)
+COMPAT_SYSCALL_DEFINE4(lookup_dcookie, u32, w0, u32, w1, char __user *, buf, compat_size_t, len)
{
#ifdef __BIG_ENDIAN
return sys_lookup_dcookie(((u64)w0 << 32) | w1, buf, len);
diff --git a/include/linux/compat.h b/include/linux/compat.h
index caa5385..df70600 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -421,7 +421,7 @@ extern long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
compat_long_t addr, compat_long_t data);

-asmlinkage long compat_sys_lookup_dcookie(u32, u32, char __user *, size_t);
+asmlinkage long compat_sys_lookup_dcookie(u32, u32, char __user *, compat_size_t);
/*
* epoll (fs/eventpoll.c) compat bits follow ...
*/
--
1.8.3.2

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