It actually turns out that the check in csum_partial_copy_from_user is pointless (the check is already done in csum_and_copy_from_user that is the only caller of csum_partial_copy_from_user).
So, please ignore this patch - we need to clean up alpha and x86 implementation of csum_partial_copy_from_user and not add this pointless check to ia64. Mikulas On Thu, 23 Jan 2014, Mikulas Patocka wrote: > ia64: validate user arguments in csum_partial_copy_from_user > > csum_partial_copy_from_user needs to validate that the argument points to > userspace and not kernelspace (see for example commit > 3ddc5b46a8e90f3c9251338b60191d0a804b0d92). Consequently, we need to use > copy_from_user instead of __copy_from_user. > > We also need to change csum_partial_copy_nocheck - this function is called > with src pointing to kernel space, so we call set_fs(KERNEL_DS) to prevent > copy_from_user from failing. > > Signed-off-by: Mikulas Patocka <[email protected]> > Cc: [email protected] > > --- > arch/ia64/lib/csum_partial_copy.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > Index: linux-2.6-ia64/arch/ia64/lib/csum_partial_copy.c > =================================================================== > --- linux-2.6-ia64.orig/arch/ia64/lib/csum_partial_copy.c 2014-01-24 > 02:40:10.000000000 +0100 > +++ linux-2.6-ia64/arch/ia64/lib/csum_partial_copy.c 2014-01-24 > 03:05:26.000000000 +0100 > @@ -116,8 +116,12 @@ csum_partial_copy_from_user(const void _ > * scared. > */ > > - if (__copy_from_user(dst, src, len) != 0 && errp) > - *errp = -EFAULT; > + if (copy_from_user(dst, src, len) != 0) { > + if (*errp) > + *errp = -EFAULT; > + memset(dst, 0, len); > + return psum; > + } > > result = do_csum(dst, len); > > @@ -133,8 +137,13 @@ EXPORT_SYMBOL(csum_partial_copy_from_use > __wsum > csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum) > { > - return csum_partial_copy_from_user((__force const void __user *)src, > - dst, len, sum, NULL); > + __wsum checksum; > + mm_segment_t oldfs = get_fs(); > + set_fs(KERNEL_DS); > + checksum = csum_partial_copy_from_user((__force const void __user *)src, > + dst, len, sum, NULL); > + set_fs(oldfs); > + return checksum; > } > > EXPORT_SYMBOL(csum_partial_copy_nocheck); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
