https://github.com/torvalds/linux
Revision 43c13605bad44b8abbc9776d6e63f62ccb7a47d6 authored by Davide Caratti on 03 December 2020, 09:46:06 UTC, committed by Jakub Kicinski on 03 December 2020, 19:13:29 UTC
when openvswitch is configured to mangle the LSE, the current value is read from the packet dereferencing 4 bytes at mpls_hdr(): ensure that the label is contained in the skb "linear" area. Found by code inspection. Fixes: d27cf5c59a12 ("net: core: add MPLS update core helper and use in OvS") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Link: https://lore.kernel.org/r/aa099f245d93218b84b5c056b67b6058ccf81a66.1606987185.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent 13de4ed
Tip revision: 43c13605bad44b8abbc9776d6e63f62ccb7a47d6 authored by Davide Caratti on 03 December 2020, 09:46:06 UTC
net: openvswitch: ensure LSE is pullable before reading it
net: openvswitch: ensure LSE is pullable before reading it
Tip revision: 43c1360
stack.c
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/fs_stack.h>
/* does _NOT_ require i_mutex to be held.
*
* This function cannot be inlined since i_size_{read,write} is rather
* heavy-weight on 32-bit systems
*/
void fsstack_copy_inode_size(struct inode *dst, struct inode *src)
{
loff_t i_size;
blkcnt_t i_blocks;
/*
* i_size_read() includes its own seqlocking and protection from
* preemption (see include/linux/fs.h): we need nothing extra for
* that here, and prefer to avoid nesting locks than attempt to keep
* i_size and i_blocks in sync together.
*/
i_size = i_size_read(src);
/*
* But on 32-bit, we ought to make an effort to keep the two halves of
* i_blocks in sync despite SMP or PREEMPTION - though stat's
* generic_fillattr() doesn't bother, and we won't be applying quotas
* (where i_blocks does become important) at the upper level.
*
* We don't actually know what locking is used at the lower level;
* but if it's a filesystem that supports quotas, it will be using
* i_lock as in inode_add_bytes().
*/
if (sizeof(i_blocks) > sizeof(long))
spin_lock(&src->i_lock);
i_blocks = src->i_blocks;
if (sizeof(i_blocks) > sizeof(long))
spin_unlock(&src->i_lock);
/*
* If CONFIG_SMP or CONFIG_PREEMPTION on 32-bit, it's vital for
* fsstack_copy_inode_size() to hold some lock around
* i_size_write(), otherwise i_size_read() may spin forever (see
* include/linux/fs.h). We don't necessarily hold i_mutex when this
* is called, so take i_lock for that case.
*
* And if on 32-bit, continue our effort to keep the two halves of
* i_blocks in sync despite SMP or PREEMPTION: use i_lock for that case
* too, and do both at once by combining the tests.
*
* There is none of this locking overhead in the 64-bit case.
*/
if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long))
spin_lock(&dst->i_lock);
i_size_write(dst, i_size);
dst->i_blocks = i_blocks;
if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long))
spin_unlock(&dst->i_lock);
}
EXPORT_SYMBOL_GPL(fsstack_copy_inode_size);
/* copy all attributes */
void fsstack_copy_attr_all(struct inode *dest, const struct inode *src)
{
dest->i_mode = src->i_mode;
dest->i_uid = src->i_uid;
dest->i_gid = src->i_gid;
dest->i_rdev = src->i_rdev;
dest->i_atime = src->i_atime;
dest->i_mtime = src->i_mtime;
dest->i_ctime = src->i_ctime;
dest->i_blkbits = src->i_blkbits;
dest->i_flags = src->i_flags;
set_nlink(dest, src->i_nlink);
}
EXPORT_SYMBOL_GPL(fsstack_copy_attr_all);
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