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683c6ba6e5
bond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and
takes RTNL via rtnl_trylock() before undoing the promiscuity it set on the
active slave. In that window the active slave can change under RTNL
(RTM_DELLINK -> __bond_release_one() -> bond_alb_handle_active_change()),
which already drops the promiscuity and clears primary_is_promisc. The
monitor still acts on the stale decision: if the slave was removed with no
failover, curr_active_slave is now NULL and the deref faults; if it failed
over, the stale dev_set_promiscuity(-1) underflows the new slave's
promiscuity counter and pins it in IFF_PROMISC.
Oops: general protection fault, probably for non-canonical address ...
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Workqueue: b42 bond_alb_monitor
RIP: 0010:bond_alb_monitor (drivers/net/bonding/bond_alb.c:1600)
process_one_work (kernel/workqueue.c:3322)
worker_thread (kernel/workqueue.c:3486)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
Kernel panic - not syncing: Fatal exception
Re-check primary_is_promisc (and curr_active_slave) after taking RTNL so
the monitor only undoes an increment it still owns. The other bonding
monitors already re-read state under RTNL in their commit phase
(bond_miimon_commit/bond_ab_arp_commit); bond_alb_monitor() was the only
one acting on the pre-trylock decision.
Fixes:
|
||
|---|---|---|
| .. | ||
| bond_3ad.c | ||
| bond_alb.c | ||
| bond_debugfs.c | ||
| bond_main.c | ||
| bond_netlink.c | ||
| bond_options.c | ||
| bond_procfs.c | ||
| bond_sysfs_slave.c | ||
| bond_sysfs.c | ||
| Makefile | ||