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authorStephen Boyd <sboyd@codeaurora.org>2014-04-18 16:29:43 -0700
committerMike Turquette <mturquette@linaro.org>2014-04-30 11:44:05 -0700
commit874f224cc52d64c912087e68e3724be95ad80ee7 (patch)
treeebb38cf26ab86021aff7c7a5d22638ded7858ba6
parent293ba3b4a4fd54891b900f2911d1a57e1ed4a843 (diff)
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clk: Fix slab corruption in clk_unregister()
When a clock is unregsitered, we iterate over the list of children and reparent them to NULL (i.e. orphan list). While iterating the list, we should use the safe iterators because the children list for this clock is changing when we reparent the children to NULL. Failure to iterate safely can lead to slab corruption like this: ============================================================================= BUG kmalloc-128 (Not tainted): Poison overwritten ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: 0xed0c4900-0xed0c4903. First byte 0x0 instead of 0x6b INFO: Allocated in clk_register+0x20/0x1bc age=297 cpu=2 pid=70 __slab_alloc.isra.39.constprop.42+0x410/0x454 kmem_cache_alloc_trace+0x200/0x24c clk_register+0x20/0x1bc devm_clk_register+0x34/0x68 0xbf0000f0 platform_drv_probe+0x18/0x48 driver_probe_device+0x94/0x360 __driver_attach+0x94/0x98 bus_for_each_dev+0x54/0x88 bus_add_driver+0xe8/0x204 driver_register+0x78/0xf4 do_one_initcall+0xc4/0x17c load_module+0x19ac/0x2294 SyS_init_module+0xa4/0x110 ret_fast_syscall+0x0/0x48 INFO: Freed in clk_unregister+0xd4/0x140 age=23 cpu=2 pid=73 __slab_free+0x38/0x41c clk_unregister+0xd4/0x140 release_nodes+0x164/0x1d8 __device_release_driver+0x60/0xb0 driver_detach+0xb4/0xb8 bus_remove_driver+0x5c/0xc4 SyS_delete_module+0x148/0x1d8 ret_fast_syscall+0x0/0x48 INFO: Slab 0xeec50b90 objects=25 used=0 fp=0xed0c5400 flags=0x4080 INFO: Object 0xed0c48c0 @offset=2240 fp=0xed0c4a00 Bytes b4 ed0c48b0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ Object ed0c48c0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c48d0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c48e0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c48f0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c4900: 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ....kkkkkkkkkkkk Object ed0c4910: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c4920: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ed0c4930: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk. Redzone ed0c4940: bb bb bb bb .... Padding ed0c49e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ Padding ed0c49f8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ CPU: 3 PID: 75 Comm: mdev Tainted: G B 3.14.0-11033-g2054ba5ca781 #35 [<c0014be0>] (unwind_backtrace) from [<c0012240>] (show_stack+0x10/0x14) [<c0012240>] (show_stack) from [<c04b74a0>] (dump_stack+0x70/0xbc) [<c04b74a0>] (dump_stack) from [<c00f7a78>] (check_bytes_and_report+0xbc/0x100) [<c00f7a78>] (check_bytes_and_report) from [<c00f7c48>] (check_object+0x18c/0x218) [<c00f7c48>] (check_object) from [<c00f7efc>] (__free_slab+0x104/0x144) [<c00f7efc>] (__free_slab) from [<c04b6668>] (__slab_free+0x3dc/0x41c) [<c04b6668>] (__slab_free) from [<c014c008>] (load_elf_binary+0x88/0x12b4) [<c014c008>] (load_elf_binary) from [<c0105a44>] (search_binary_handler+0x78/0x18c) [<c0105a44>] (search_binary_handler) from [<c0106fc0>] (do_execve+0x490/0x5dc) [<c0106fc0>] (do_execve) from [<c0036b8c>] (____call_usermodehelper+0x134/0x168) [<c0036b8c>] (____call_usermodehelper) from [<c000f048>] (ret_from_fork+0x14/0x2c) FIX kmalloc-128: Restoring 0xed0c4900-0xed0c4903=0x6b Fixes: fcb0ee6a3d33 (clk: Implement clk_unregister) Cc: Jiada Wang <jiada_wang@mentor.com> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Mike Turquette <mturquette@linaro.org> Cc: stable@vger.kernel.org
-rw-r--r--drivers/clk/clk.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f71093bf83ab..7cf2c093cc54 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2140,9 +2140,10 @@ void clk_unregister(struct clk *clk)
if (!hlist_empty(&clk->children)) {
struct clk *child;
+ struct hlist_node *t;
/* Reparent all children to the orphan list. */
- hlist_for_each_entry(child, &clk->children, child_node)
+ hlist_for_each_entry_safe(child, t, &clk->children, child_node)
clk_set_parent(child, NULL);
}