4.15-stable review patch. If anyone has any objections, please let me know.
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From: Jason Gunthorpe jgg@mellanox.com
commit 9137108cc3d64ade13e753108ec611a0daed16a0 upstream.
process_one_req() can race with rdma_addr_cancel():
CPU0 CPU1 ==== ==== process_one_work() debug_work_deactivate(work); process_one_req() rdma_addr_cancel() mutex_lock(&lock); set_timeout(&req->work,..); __queue_work() debug_work_activate(work); mutex_unlock(&lock);
mutex_lock(&lock); [..] list_del(&req->list); mutex_unlock(&lock); [..]
// ODEBUG explodes since the work is still queued. kfree(req);
Causing ODEBUG to detect the use after free:
ODEBUG: free active (active state 0) object type: work_struct hint: process_one_req+0x0/0x6c0 include/net/dst.h:165 WARNING: CPU: 0 PID: 79 at lib/debugobjects.c:291 debug_print_object+0x166/0x220 lib/debugobjects.c:288 kvm: emulating exchange as write Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 79 Comm: kworker/u4:3 Not tainted 4.16.0-rc6+ #361 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ib_addr process_one_req Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 panic+0x1e4/0x41c kernel/panic.c:183 __warn+0x1dc/0x200 kernel/panic.c:547 report_bug+0x1f4/0x2b0 lib/bug.c:186 fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 fixup_bug arch/x86/kernel/traps.c:247 [inline] do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 RIP: 0010:debug_print_object+0x166/0x220 lib/debugobjects.c:288 RSP: 0000:ffff8801d966f210 EFLAGS: 00010086 RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff815acd6e RDX: 0000000000000000 RSI: 1ffff1003b2cddf2 RDI: 0000000000000000 RBP: ffff8801d966f250 R08: 0000000000000000 R09: 1ffff1003b2cddc8 R10: ffffed003b2cde71 R11: ffffffff86f39a98 R12: 0000000000000001 R13: ffffffff86f15540 R14: ffffffff86408700 R15: ffffffff8147c0a0 __debug_check_no_obj_freed lib/debugobjects.c:745 [inline] debug_check_no_obj_freed+0x662/0xf1f lib/debugobjects.c:774 kfree+0xc7/0x260 mm/slab.c:3799 process_one_req+0x2e7/0x6c0 drivers/infiniband/core/addr.c:592 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Fixes: 5fff41e1f89d ("IB/core: Fix race condition in resolving IP to MAC") Reported-by: syzbot+3b4acab09b6463472d0a@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/addr.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/infiniband/core/addr.c +++ b/drivers/infiniband/core/addr.c @@ -598,6 +598,15 @@ static void process_one_req(struct work_ list_del(&req->list); mutex_unlock(&lock);
+ /* + * Although the work will normally have been canceled by the + * workqueue, it can still be requeued as long as it is on the + * req_list, so it could have been requeued before we grabbed &lock. + * We need to cancel it after it is removed from req_list to really be + * sure it is safe to free. + */ + cancel_delayed_work(&req->work); + req->callback(req->status, (struct sockaddr *)&req->src_addr, req->addr, req->context); put_client(req->client);