From: Chen-Yu Tsai wens@csie.org
[ Upstream commit 58799865be84e2a895dab72de0e1b996ed943f22 ]
The dsa framework has optional .port_mdb_{prepare,add,del} callback fields for drivers to handle multicast database entries. When adding an entry, the framework goes through a prepare phase, then a commit phase. Drivers not providing these callbacks should be detected in the prepare phase.
DSA core may still bypass the bridge layer and call the dsa_port_mdb_add function directly with no prepare phase or no switchdev trans object, and the framework ends up calling an undefined .port_mdb_add callback. This results in a NULL pointer dereference, as shown in the log below.
The other functions seem to be properly guarded. Do the same for .port_mdb_add in dsa_switch_mdb_add_bitmap() as well.
8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = (ptrval) [00000000] *pgd=00000000 Internal error: Oops: 80000005 [#1] SMP ARM Modules linked in: rtl8xxxu rtl8192cu rtl_usb rtl8192c_common rtlwifi mac80211 cfg80211 CPU: 1 PID: 134 Comm: kworker/1:2 Not tainted 5.3.0-rc1-00247-gd3519030752a #1 Hardware name: Allwinner sun7i (A20) Family Workqueue: events switchdev_deferred_process_work PC is at 0x0 LR is at dsa_switch_event+0x570/0x620 pc : [<00000000>] lr : [<c08533ec>] psr: 80070013 sp : ee871db8 ip : 00000000 fp : ee98d0a4 r10: 0000000c r9 : 00000008 r8 : ee89f710 r7 : ee98d040 r6 : ee98d088 r5 : c0f04c48 r4 : ee98d04c r3 : 00000000 r2 : ee89f710 r1 : 00000008 r0 : ee98d040 Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 6deb406a DAC: 00000051 Process kworker/1:2 (pid: 134, stack limit = 0x(ptrval)) Stack: (0xee871db8 to 0xee872000) 1da0: ee871e14 103ace2d 1dc0: 00000000 ffffffff 00000000 ee871e14 00000005 00000000 c08524a0 00000000 1de0: ffffe000 c014bdfc c0f04c48 ee871e98 c0f04c48 ee9e5000 c0851120 c014bef0 1e00: 00000000 b643aea2 ee9b4068 c08509a8 ee2bf940 ee89f710 ee871ecb 00000000 1e20: 00000008 103ace2d 00000000 c087e248 ee29c868 103ace2d 00000001 ffffffff 1e40: 00000000 ee871e98 00000006 00000000 c0fb2a50 c087e2d0 ffffffff c08523c4 1e60: ffffffff c014bdfc 00000006 c0fad2d0 ee871e98 ee89f710 00000000 c014c500 1e80: 00000000 ee89f3c0 c0f04c48 00000000 ee9e5000 c087dfb4 ee9e5000 00000000 1ea0: ee89f710 ee871ecb 00000001 103ace2d 00000000 c0f04c48 00000000 c087e0a8 1ec0: 00000000 efd9a3e0 0089f3c0 103ace2d ee89f700 ee89f710 ee9e5000 00000122 1ee0: 00000100 c087e130 ee89f700 c0fad2c8 c1003ef0 c087de4c 2e928000 c0fad2ec 1f00: c0fad2ec ee839580 ef7a62c0 ef7a9400 00000000 c087def8 c0fad2ec c01447dc 1f20: ef315640 ef7a62c0 00000008 ee839580 ee839594 ef7a62c0 00000008 c0f03d00 1f40: ef7a62d8 ef7a62c0 ffffe000 c0145b84 ffffe000 c0fb2420 c0bfaa8c 00000000 1f60: ffffe000 ee84b600 ee84b5c0 00000000 ee870000 ee839580 c0145b40 ef0e5ea4 1f80: ee84b61c c014a6f8 00000001 ee84b5c0 c014a5b0 00000000 00000000 00000000 1fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [<c08533ec>] (dsa_switch_event) from [<c014bdfc>] (notifier_call_chain+0x48/0x84) [<c014bdfc>] (notifier_call_chain) from [<c014bef0>] (raw_notifier_call_chain+0x18/0x20) [<c014bef0>] (raw_notifier_call_chain) from [<c08509a8>] (dsa_port_mdb_add+0x48/0x74) [<c08509a8>] (dsa_port_mdb_add) from [<c087e248>] (__switchdev_handle_port_obj_add+0x54/0xd4) [<c087e248>] (__switchdev_handle_port_obj_add) from [<c087e2d0>] (switchdev_handle_port_obj_add+0x8/0x14) [<c087e2d0>] (switchdev_handle_port_obj_add) from [<c08523c4>] (dsa_slave_switchdev_blocking_event+0x94/0xa4) [<c08523c4>] (dsa_slave_switchdev_blocking_event) from [<c014bdfc>] (notifier_call_chain+0x48/0x84) [<c014bdfc>] (notifier_call_chain) from [<c014c500>] (blocking_notifier_call_chain+0x50/0x68) [<c014c500>] (blocking_notifier_call_chain) from [<c087dfb4>] (switchdev_port_obj_notify+0x44/0xa8) [<c087dfb4>] (switchdev_port_obj_notify) from [<c087e0a8>] (switchdev_port_obj_add_now+0x90/0x104) [<c087e0a8>] (switchdev_port_obj_add_now) from [<c087e130>] (switchdev_port_obj_add_deferred+0x14/0x5c) [<c087e130>] (switchdev_port_obj_add_deferred) from [<c087de4c>] (switchdev_deferred_process+0x64/0x104) [<c087de4c>] (switchdev_deferred_process) from [<c087def8>] (switchdev_deferred_process_work+0xc/0x14) [<c087def8>] (switchdev_deferred_process_work) from [<c01447dc>] (process_one_work+0x218/0x50c) [<c01447dc>] (process_one_work) from [<c0145b84>] (worker_thread+0x44/0x5bc) [<c0145b84>] (worker_thread) from [<c014a6f8>] (kthread+0x148/0x150) [<c014a6f8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c) Exception stack(0xee871fb0 to 0xee871ff8) 1fa0: 00000000 00000000 00000000 00000000 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 Code: bad PC value ---[ end trace 1292c61abd17b130 ]---
[<c08533ec>] (dsa_switch_event) from [<c014bdfc>] (notifier_call_chain+0x48/0x84) corresponds to
$ arm-linux-gnueabihf-addr2line -C -i -e vmlinux c08533ec
linux/net/dsa/switch.c:156 linux/net/dsa/switch.c:178 linux/net/dsa/switch.c:328
Fixes: e6db98db8a95 ("net: dsa: add switch mdb bitmap functions") Signed-off-by: Chen-Yu Tsai wens@csie.org Reviewed-by: Vivien Didelot vivien.didelot@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/dsa/switch.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/dsa/switch.c b/net/dsa/switch.c index 4ec5b7f85d51e..09d9286b27ccb 100644 --- a/net/dsa/switch.c +++ b/net/dsa/switch.c @@ -153,6 +153,9 @@ static void dsa_switch_mdb_add_bitmap(struct dsa_switch *ds, { int port;
+ if (!ds->ops->port_mdb_add) + return; + for_each_set_bit(port, bitmap, ds->num_ports) ds->ops->port_mdb_add(ds, port, mdb); }