Messages in this thread Patch in this message | | | Date | Tue, 4 Nov 2008 15:33:36 -0800 | From | Greg KH <> | Subject | [patch 56/57] bonding: fix panic when taking bond interface down before removing module |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------ From: Andy Gospodarek <andy@greyhouse.net>
commit ce39a800ea87c655de49af021c8b20ee323cb40d upstream.
A panic was discovered with bonding when using mode 5 or 6 and trying to remove the slaves from the bond after the interface was taken down. When calling 'ifconfig bond0 down' the following happens:
bond_close() bond_alb_deinitialize() tlb_deinitialize() kfree(bond_info->tx_hashtbl) bond_info->tx_hashtbl = NULL
Unfortunately if there are still slaves in the bond, when removing the module the following happens:
bonding_exit() bond_free_all() bond_release_all() bond_alb_deinit_slave() tlb_clear_slave() tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl u32 next_index = tx_hash_table[index].next
As you might guess we panic when trying to access a few entries into the table that no longer exists.
I experimented with several options (like moving the calls to tlb_deinitialize somewhere else), but it really makes the most sense to be part of the bond_close routine. It also didn't seem logical move tlb_clear_slave around too much, so the simplest option seems to add a check in tlb_clear_slave to make sure we haven't already wiped the tx_hashtbl away before searching for all the non-existent hash-table entries that used to point to the slave as the output interface.
Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/net/bonding/bond_alb.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
--- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c @@ -167,11 +167,14 @@ static void tlb_clear_slave(struct bondi /* clear slave from tx_hashtbl */ tx_hash_table = BOND_ALB_INFO(bond).tx_hashtbl; - index = SLAVE_TLB_INFO(slave).head; - while (index != TLB_NULL_INDEX) { - u32 next_index = tx_hash_table[index].next; - tlb_init_table_entry(&tx_hash_table[index], save_load); - index = next_index; + /* skip this if we've already freed the tx hash table */ + if (tx_hash_table) { + index = SLAVE_TLB_INFO(slave).head; + while (index != TLB_NULL_INDEX) { + u32 next_index = tx_hash_table[index].next; + tlb_init_table_entry(&tx_hash_table[index], save_load); + index = next_index; + } } tlb_init_slave(slave); --
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