linux-toradex.git/fs/compat.c, branch v3.0.95

Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys

2013-03-28T19:06:04+00:00

commit 8aec0f5d4137532de14e6554fd5dd201ff3a3c49 upstream.

Looking at mm/process_vm_access.c:process_vm_rw() and comparing it to
compat_process_vm_rw() shows that the compatibility code requires an
explicit "access_ok()" check before calling
compat_rw_copy_check_uvector(). The same difference seems to appear when
we compare fs/read_write.c:do_readv_writev() to
fs/compat.c:compat_do_readv_writev().

This subtle difference between the compat and non-compat requirements
should probably be debated, as it seems to be error-prone. In fact,
there are two others sites that use this function in the Linux kernel,
and they both seem to get it wrong:

Now shifting our attention to fs/aio.c, we see that aio_setup_iocb()
also ends up calling compat_rw_copy_check_uvector() through
aio_setup_vectored_rw(). Unfortunately, the access_ok() check appears to
be missing. Same situation for
security/keys/compat.c:compat_keyctl_instantiate_key_iov().

I propose that we add the access_ok() check directly into
compat_rw_copy_check_uvector(), so callers don't have to worry about it,
and it therefore makes the compat call code similar to its non-compat
counterpart. Place the access_ok() check in the same location where
copy_from_user() can trigger a -EFAULT error in the non-compat code, so
the ABI behaviors are alike on both compat and non-compat.

While we are here, fix compat_do_readv_writev() so it checks for
compat_rw_copy_check_uvector() negative return values.

And also, fix a memory leak in compat_keyctl_instantiate_key_iov() error
handling.

Acked-by: Linus Torvalds 
Acked-by: Al Viro 
Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

vfs: missed source of ->f_pos races

2012-09-14T17:00:37+00:00

commit 0e665d5d1125f9f4ccff56a75e814f10f88861a2 upstream.

compat_sys_{read,write}v() need the same "pass a copy of file->f_pos" thing
as sys_{read,write}{,v}().

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

exec: unify do_execve/compat_do_execve code

2011-04-09T13:53:56+00:00

Add the appropriate members into struct user_arg_ptr and teach
get_user_arg_ptr() to handle is_compat = T case correctly.

This allows us to remove the compat_do_execve() code from fs/compat.c
and reimplement compat_do_execve() as the trivial wrapper on top of
do_execve_common(is_compat => true).

In fact, this fixes another (minor) bug. "compat_uptr_t str" can
overflow after "str += len" in compat_copy_strings() if a 64bit
application execs via sys32_execve().

Unexport acct_arg_size() and get_arg_page(), fs/compat.c doesn't
need them any longer.

Signed-off-by: Oleg Nesterov 
Reviewed-by: KOSAKI Motohiro 
Tested-by: KOSAKI Motohiro

select: remove unused MAX_SELECT_SECONDS

2011-03-21T04:16:08+00:00

Remove the leftover from the commit 8ff3e8e85fa6 ("select:
switch select() and poll() over to hrtimers").

Signed-off-by: Namhyung Kim 
Acked-by: Arjan van de Ven 
Signed-off-by: Al Viro

vfs: Add open by file handle support

2011-03-15T06:21:44+00:00

[AV: duplicate of open() guts removed; file_open_root() used instead]

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Al Viro

clean statfs-like syscalls up

2011-03-14T13:15:28+00:00

New helpers: user_statfs() and fd_statfs(), taking userland pathname and
descriptor resp. and filling struct kstatfs.  Syscalls of statfs family
(native, compat and foreign - osf and hpux on alpha and parisc resp.)
switched to those.  Removes some boilerplate code, simplifies cleanup
on errors...

Signed-off-by: Al Viro

compat breakage in preadv() and pwritev()

2011-03-13T23:21:26+00:00

Fix for a dumb preadv()/pwritev() compat bug - unlike the native
variants, compat_... ones forget to check FMODE_P{READ,WRITE}, so e.g.
on pipe the native preadv() will fail with -ESPIPE and compat one will
act as readv() and succeed.  Not critical, but it's a clear bug with trivial
fix.

Signed-off-by: Al Viro

compat: copy missing fields in compat_statfs64 to user

2011-01-17T09:54:38+00:00

f_flags and f_spare fields were not copied to userspace when
compat_sys_[f]statfs64 called.

Signed-off-by: Namhyung Kim 
Cc: Christoph Hellwig 
Signed-off-by: Al Viro

compat: update comment of compat statfs syscalls

2011-01-17T09:54:38+00:00

The commit 7ed1ee6118ae ("Take statfs variants to fs/statfs.c")
separates out statfs syscalls from fs/open.c. Thus the comment
should be changed also.

Signed-off-by: Namhyung Kim 
Cc: Jiri Kosina 
Signed-off-by: Al Viro

compat: remove unnecessary assignment in compat_rw_copy_check_uvector()

2011-01-17T09:54:38+00:00

*@ret_pointer is initialized to @fast_pointer thus the assignment is
redundant.

Signed-off-by: Namhyung Kim 
Cc: Jeff Moyer 
Signed-off-by: Al Viro