Revision 4e43e64d0f1332fcc503babad4dc31aead7131ca authored by Eric Dumazet on 28 June 2022, 12:12:48 UTC, committed by Jakub Kicinski on 30 June 2022, 03:41:09 UTC
As reported by syzbot, we should not use rcu_dereference()
when rcu_read_lock() is not held.
WARNING: suspicious RCU usage
5.19.0-rc2-syzkaller #0 Not tainted
net/ipv6/addrconf.c:5175 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor326/3617:
#0: ffffffff8d5848e8 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0xae/0xc20 net/netlink/af_netlink.c:2223
stack backtrace:
CPU: 0 PID: 3617 Comm: syz-executor326 Not tainted 5.19.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
in6_dump_addrs+0x12d1/0x1790 net/ipv6/addrconf.c:5175
inet6_dump_addr+0x9c1/0xb50 net/ipv6/addrconf.c:5300
netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275
__netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380
netlink_dump_start include/linux/netlink.h:245 [inline]
rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2492
___sys_sendmsg+0xf3/0x170 net/socket.c:2546
__sys_sendmsg net/socket.c:2575 [inline]
__do_sys_sendmsg net/socket.c:2584 [inline]
__se_sys_sendmsg net/socket.c:2582 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2582
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Fixes: 88e2ca308094 ("mld: convert ifmcaddr6 to RCU")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20220628121248.858695-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1 parent fa152f6
interval_tree.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* mm/interval_tree.c - interval tree for mapping->i_mmap
*
* Copyright (C) 2012, Michel Lespinasse <walken@google.com>
*/
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/rmap.h>
#include <linux/interval_tree_generic.h>
static inline unsigned long vma_start_pgoff(struct vm_area_struct *v)
{
return v->vm_pgoff;
}
static inline unsigned long vma_last_pgoff(struct vm_area_struct *v)
{
return v->vm_pgoff + vma_pages(v) - 1;
}
INTERVAL_TREE_DEFINE(struct vm_area_struct, shared.rb,
unsigned long, shared.rb_subtree_last,
vma_start_pgoff, vma_last_pgoff, /* empty */, vma_interval_tree)
/* Insert node immediately after prev in the interval tree */
void vma_interval_tree_insert_after(struct vm_area_struct *node,
struct vm_area_struct *prev,
struct rb_root_cached *root)
{
struct rb_node **link;
struct vm_area_struct *parent;
unsigned long last = vma_last_pgoff(node);
VM_BUG_ON_VMA(vma_start_pgoff(node) != vma_start_pgoff(prev), node);
if (!prev->shared.rb.rb_right) {
parent = prev;
link = &prev->shared.rb.rb_right;
} else {
parent = rb_entry(prev->shared.rb.rb_right,
struct vm_area_struct, shared.rb);
if (parent->shared.rb_subtree_last < last)
parent->shared.rb_subtree_last = last;
while (parent->shared.rb.rb_left) {
parent = rb_entry(parent->shared.rb.rb_left,
struct vm_area_struct, shared.rb);
if (parent->shared.rb_subtree_last < last)
parent->shared.rb_subtree_last = last;
}
link = &parent->shared.rb.rb_left;
}
node->shared.rb_subtree_last = last;
rb_link_node(&node->shared.rb, &parent->shared.rb, link);
rb_insert_augmented(&node->shared.rb, &root->rb_root,
&vma_interval_tree_augment);
}
static inline unsigned long avc_start_pgoff(struct anon_vma_chain *avc)
{
return vma_start_pgoff(avc->vma);
}
static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc)
{
return vma_last_pgoff(avc->vma);
}
INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last,
avc_start_pgoff, avc_last_pgoff,
static inline, __anon_vma_interval_tree)
void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
struct rb_root_cached *root)
{
#ifdef CONFIG_DEBUG_VM_RB
node->cached_vma_start = avc_start_pgoff(node);
node->cached_vma_last = avc_last_pgoff(node);
#endif
__anon_vma_interval_tree_insert(node, root);
}
void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
struct rb_root_cached *root)
{
__anon_vma_interval_tree_remove(node, root);
}
struct anon_vma_chain *
anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
unsigned long first, unsigned long last)
{
return __anon_vma_interval_tree_iter_first(root, first, last);
}
struct anon_vma_chain *
anon_vma_interval_tree_iter_next(struct anon_vma_chain *node,
unsigned long first, unsigned long last)
{
return __anon_vma_interval_tree_iter_next(node, first, last);
}
#ifdef CONFIG_DEBUG_VM_RB
void anon_vma_interval_tree_verify(struct anon_vma_chain *node)
{
WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node));
WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node));
}
#endif
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