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5d066766c5
In l2tp's net exit handler, we check that an IDR is empty before
destroying it:
WARN_ON_ONCE(!idr_is_empty(&pn->l2tp_tunnel_idr));
idr_destroy(&pn->l2tp_tunnel_idr);
By forcing memory allocation failures in idr_alloc_32, syzbot is able
to provoke a condition where idr_is_empty returns false despite there
being no items in the IDR. This turns out to be because the radix tree
of the IDR contains only internal radix-tree nodes and it is this that
causes idr_is_empty to return false. The internal nodes are cleaned by
idr_destroy.
Use idr_for_each to check that the IDR is empty instead of
idr_is_empty to avoid the problem.
Reported-by: syzbot+332fe1e67018625f63c9@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=332fe1e67018625f63c9
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| l2tp_core.c | ||
| l2tp_core.h | ||
| l2tp_debugfs.c | ||
| l2tp_eth.c | ||
| l2tp_ip6.c | ||
| l2tp_ip.c | ||
| l2tp_netlink.c | ||
| l2tp_ppp.c | ||
| Makefile | ||
| trace.h | ||