[ 3.8.y.z extended stable ] Patch "clk: remove notifier from list before freeing it" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Tue Jun 25 22:20:01 UTC 2013
This is a note to let you know that I have just added a patch titled
clk: remove notifier from list before freeing it
to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue
This patch is scheduled to be released in version 3.8.13.4.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From e7eb56db5da4a32206f8ef5b43bc54946c94544e Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs at cn.fujitsu.com>
Date: Mon, 3 Jun 2013 17:17:15 +0800
Subject: clk: remove notifier from list before freeing it
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
commit 72b5322f11ff0abf6a52b3007486656578d2c982 upstream.
The @cn is stay in @clk_notifier_list after it is freed, it cause
memory corruption.
Example, if @clk is registered(first), unregistered(first),
registered(second), unregistered(second).
The freed @cn will be used when @clk is registered(second),
and the bug will be happened when @clk is unregistered(second):
[ 517.040000] clk_notif_dbg clk_notif_dbg.1: clk_notifier_unregister()
[ 517.040000] Unable to handle kernel paging request at virtual address 00df3008
[ 517.050000] pgd = ed858000
[ 517.050000] [00df3008] *pgd=00000000
[ 517.060000] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[ 517.060000] Modules linked in: clk_notif_dbg(O-) [last unloaded: clk_notif_dbg]
[ 517.060000] CPU: 1 PID: 499 Comm: modprobe Tainted: G O 3.10.0-rc3-00119-ga93cb29-dirty #85
[ 517.060000] task: ee1e0180 ti: ee3e6000 task.ti: ee3e6000
[ 517.060000] PC is at srcu_readers_seq_idx+0x48/0x84
[ 517.060000] LR is at srcu_readers_seq_idx+0x60/0x84
[ 517.060000] pc : [<c0052720>] lr : [<c0052738>] psr: 80070013
[ 517.060000] sp : ee3e7d48 ip : 00000000 fp : ee3e7d6c
[ 517.060000] r10: 00000000 r9 : ee3e6000 r8 : 00000000
[ 517.060000] r7 : ed84fe4c r6 : c068ec90 r5 : c068e430 r4 : 00000000
[ 517.060000] r3 : 00df3000 r2 : 00000000 r1 : 00000002 r0 : 00000000
[ 517.060000] Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 517.060000] Control: 18c5387d Table: 2d85804a DAC: 00000015
[ 517.060000] Process modprobe (pid: 499, stack limit = 0xee3e6238)
[ 517.060000] Stack: (0xee3e7d48 to 0xee3e8000)
....
[ 517.060000] [<c0052720>] (srcu_readers_seq_idx+0x48/0x84) from [<c0052790>] (try_check_zero+0x34/0xfc)
[ 517.060000] [<c0052790>] (try_check_zero+0x34/0xfc) from [<c00528b0>] (srcu_advance_batches+0x58/0x114)
[ 517.060000] [<c00528b0>] (srcu_advance_batches+0x58/0x114) from [<c0052c30>] (__synchronize_srcu+0x114/0x1ac)
[ 517.060000] [<c0052c30>] (__synchronize_srcu+0x114/0x1ac) from [<c0052d14>] (synchronize_srcu+0x2c/0x34)
[ 517.060000] [<c0052d14>] (synchronize_srcu+0x2c/0x34) from [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74)
[ 517.060000] [<c0053a08>] (srcu_notifier_chain_unregister+0x68/0x74) from [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0)
[ 517.060000] [<c0375a78>] (clk_notifier_unregister+0x7c/0xc0) from [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg])
[ 517.060000] [<bf008034>] (clk_notif_dbg_remove+0x34/0x9c [clk_notif_dbg]) from [<c02bb974>] (platform_drv_remove+0x24/0x28)
[ 517.060000] [<c02bb974>] (platform_drv_remove+0x24/0x28) from [<c02b9bf8>] (__device_release_driver+0x8c/0xd4)
[ 517.060000] [<c02b9bf8>] (__device_release_driver+0x8c/0xd4) from [<c02ba680>] (driver_detach+0x9c/0xc4)
[ 517.060000] [<c02ba680>] (driver_detach+0x9c/0xc4) from [<c02b99c4>] (bus_remove_driver+0xcc/0xfc)
[ 517.060000] [<c02b99c4>] (bus_remove_driver+0xcc/0xfc) from [<c02bace4>] (driver_unregister+0x54/0x78)
[ 517.060000] [<c02bace4>] (driver_unregister+0x54/0x78) from [<c02bbb44>] (platform_driver_unregister+0x1c/0x20)
[ 517.060000] [<c02bbb44>] (platform_driver_unregister+0x1c/0x20) from [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg])
[ 517.060000] [<bf0081f8>] (clk_notif_dbg_driver_exit+0x14/0x1c [clk_notif_dbg]) from [<c00835e4>] (SyS_delete_module+0x200/0x28c)
[ 517.060000] [<c00835e4>] (SyS_delete_module+0x200/0x28c) from [<c000edc0>] (ret_fast_syscall+0x0/0x48)
[ 517.060000] Code: e5973004 e7911102 e0833001 e2881002 (e7933101)
Reported-by: Sören Brinkmann <soren.brinkmann at xilinx.com>
Signed-off-by: Lai Jiangshan <laijs at cn.fujitsu.com>
Tested-by: Sören Brinkmann <soren.brinkmann at xilinx.com>
Signed-off-by: Mike Turquette <mturquette at linaro.org>
[mturquette at linaro.org: shortened $SUBJECT]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/clk/clk.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 251e45d..e3b8b2c 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1633,6 +1633,7 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
/* XXX the notifier code should handle this better */
if (!cn->notifier_head.head) {
srcu_cleanup_notifier_head(&cn->notifier_head);
+ list_del(&cn->node);
kfree(cn);
}
--
1.8.1.2
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