aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBorislav Petkov <bp@suse.de>2015-12-01 15:52:36 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-09 15:31:53 -0800
commit9f2c4c9b3e4b2647af324d565f401e2b6fc96649 (patch)
tree02980600d45f257bfca88196b57df4972b8f4196
parent29ec60ccee541893e18a749044084fc2caa79137 (diff)
downloadlinux-linaro-stable-9f2c4c9b3e4b2647af324d565f401e2b6fc96649.tar.gz
EDAC, mc_sysfs: Fix freeing bus' name
commit 12e26969b32c79018165d52caff3762135614aa1 upstream. I get the splat below when modprobing/rmmoding EDAC drivers. It happens because bus->name is invalid after bus_unregister() has run. The Code: section below corresponds to: .loc 1 1108 0 movq 672(%rbx), %rax # mci_1(D)->bus, mci_1(D)->bus .loc 1 1109 0 popq %rbx # .loc 1 1108 0 movq (%rax), %rdi # _7->name, jmp kfree # and %rax has some funky stuff 2030203020312030 which looks a lot like something walked over it. Fix that by saving the name ptr before doing stuff to string it points to. general protection fault: 0000 [#1] SMP Modules linked in: ... CPU: 4 PID: 10318 Comm: modprobe Tainted: G I EN 3.12.51-11-default+ #48 Hardware name: HP ProLiant DL380 G7, BIOS P67 05/05/2011 task: ffff880311320280 ti: ffff88030da3e000 task.ti: ffff88030da3e000 RIP: 0010:[<ffffffffa019da92>] [<ffffffffa019da92>] edac_unregister_sysfs+0x22/0x30 [edac_core] RSP: 0018:ffff88030da3fe28 EFLAGS: 00010292 RAX: 2030203020312030 RBX: ffff880311b4e000 RCX: 000000000000095c RDX: 0000000000000001 RSI: ffff880327bb9600 RDI: 0000000000000286 RBP: ffff880311b4e750 R08: 0000000000000000 R09: ffffffff81296110 R10: 0000000000000400 R11: 0000000000000000 R12: ffff88030ba1ac68 R13: 0000000000000001 R14: 00000000011b02f0 R15: 0000000000000000 FS: 00007fc9bf8f5700(0000) GS:ffff8801a7c40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000403c90 CR3: 000000019ebdf000 CR4: 00000000000007e0 Stack: Call Trace: i7core_unregister_mci.isra.9 i7core_remove pci_device_remove __device_release_driver driver_detach bus_remove_driver pci_unregister_driver i7core_exit SyS_delete_module system_call_fastpath 0x7fc9bf426536 Code: 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 53 48 89 fb e8 52 2a 1f e1 48 8b bb a0 02 00 00 e8 46 59 1f e1 48 8b 83 a0 02 00 00 5b <48> 8b 38 e9 26 9a fe e0 66 0f 1f 44 00 00 66 66 66 66 90 48 8b RIP [<ffffffffa019da92>] edac_unregister_sysfs+0x22/0x30 [edac_core] RSP <ffff88030da3fe28> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Fixes: 7a623c039075 ("edac: rewrite the sysfs code to use struct device") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/edac/edac_mc_sysfs.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index 88cd940ece63..453c816b4537 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -973,21 +973,26 @@ nomem:
*/
int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
{
+ char *name;
int i, err;
/*
* The memory controller needs its own bus, in order to avoid
* namespace conflicts at /sys/bus/edac.
*/
- mci->bus->name = kasprintf(GFP_KERNEL, "mc%d", mci->mc_idx);
- if (!mci->bus->name)
+ name = kasprintf(GFP_KERNEL, "mc%d", mci->mc_idx);
+ if (!name)
return -ENOMEM;
+ mci->bus->name = name;
+
edac_dbg(0, "creating bus %s\n", mci->bus->name);
err = bus_register(mci->bus);
- if (err < 0)
+ if (err < 0) {
+ kfree(name);
return err;
+ }
/* get the /sys/devices/system/edac subsys reference */
mci->dev.type = &mci_attr_type;
@@ -1071,7 +1076,8 @@ fail:
fail2:
device_unregister(&mci->dev);
bus_unregister(mci->bus);
- kfree(mci->bus->name);
+ kfree(name);
+
return err;
}
@@ -1102,10 +1108,12 @@ void edac_remove_sysfs_mci_device(struct mem_ctl_info *mci)
void edac_unregister_sysfs(struct mem_ctl_info *mci)
{
+ const char *name = mci->bus->name;
+
edac_dbg(1, "Unregistering device %s\n", dev_name(&mci->dev));
device_unregister(&mci->dev);
bus_unregister(mci->bus);
- kfree(mci->bus->name);
+ kfree(name);
}
static void mc_attr_release(struct device *dev)