| From 12e26969b32c79018165d52caff3762135614aa1 Mon Sep 17 00:00:00 2001 |
| From: Borislav Petkov <bp@suse.de> |
| Date: Tue, 1 Dec 2015 15:52:36 +0100 |
| Subject: EDAC, mc_sysfs: Fix freeing bus' name |
| |
| From: Borislav Petkov <bp@suse.de> |
| |
| 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> |
| |
| --- |
| drivers/edac/edac_mc_sysfs.c | 18 +++++++++++++----- |
| 1 file changed, 13 insertions(+), 5 deletions(-) |
| |
| --- 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 |
| |
| 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) |