[PATCH] Fix 32bit sendmsg() flaw

When we copy 32bit ->msg_control contents to kernel, we walk the same
userland data twice without sanity checks on the second pass.

Second version of this patch: the original broke with 64-bit arches
running 32-bit-compat-mode executables doing sendmsg() syscalls with
unaligned CMSG data areas

Another thing is that we use kmalloc() to allocate and sock_kfree_s()
to free afterwards; less serious, but also needs fixing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Al Viro 2005-09-07 18:28:51 -07:00 committed by Linus Torvalds
parent 5aa3b610a7
commit 8920e8f94c
3 changed files with 29 additions and 20 deletions

View file

@ -33,7 +33,7 @@ extern asmlinkage long compat_sys_sendmsg(int,struct compat_msghdr __user *,unsi
extern asmlinkage long compat_sys_recvmsg(int,struct compat_msghdr __user *,unsigned);
extern asmlinkage long compat_sys_getsockopt(int, int, int, char __user *, int __user *);
extern int put_cmsg_compat(struct msghdr*, int, int, int, void *);
extern int cmsghdr_from_user_compat_to_kern(struct msghdr *, unsigned char *,
extern int cmsghdr_from_user_compat_to_kern(struct msghdr *, struct sock *, unsigned char *,
int);
#endif /* NET_COMPAT_H */