linux/drivers/edac
Shaun Ruffell faa2ad09c0 edac_mc: edac_mc_free() cannot assume mem_ctl_info is registered in sysfs.
Fix potential NULL pointer dereference in edac_unregister_sysfs() on
system boot introduced in 3.6-rc1.

Since commit 7a623c039 ("edac: rewrite the sysfs code to use struct
device") edac_mc_alloc() no longer initializes embedded kobjects in
struct mem_ctl_info.  Therefore edac_mc_free() can no longer simply
decrement a kobject reference count to free the allocated memory unless
the memory controller driver module had also called edac_mc_add_mc().

Now edac_mc_free() will check if the newly embedded struct device has
been registered with sysfs before using either the standard device
release functions or freeing the data structures itself with logic
pulled out of the error path of edac_mc_alloc().

The BUG this patch resolves for me:

  BUG: unable to handle kernel NULL pointer dereference at   (null)
  EIP is at __wake_up_common+0x1a/0x6a
  Process modprobe (pid: 933, ti=f3dc6000 task=f3db9520 task.ti=f3dc6000)
  Call Trace:
    complete_all+0x3f/0x50
    device_pm_remove+0x23/0xa2
    device_del+0x34/0x142
    edac_unregister_sysfs+0x3b/0x5c [edac_core]
    edac_mc_free+0x29/0x2f [edac_core]
    e7xxx_probe1+0x268/0x311 [e7xxx_edac]
    e7xxx_init_one+0x56/0x61 [e7xxx_edac]
    local_pci_probe+0x13/0x15
  ...

Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-23 14:46:40 -07:00
..
Kconfig edac: add support for Calxeda highbank L2 cache ecc 2012-06-27 09:01:29 -03:00
Makefile edac: add support for Calxeda highbank L2 cache ecc 2012-06-27 09:01:29 -03:00
amd64_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
amd64_edac.h amd64_edac: convert sysfs logic to use struct device 2012-06-11 13:23:40 -03:00
amd64_edac_dbg.c amd64_edac: convert sysfs logic to use struct device 2012-06-11 13:23:40 -03:00
amd64_edac_inj.c edac: Convert debugfX to edac_dbg(X, 2012-06-11 13:23:49 -03:00
amd76x_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
amd8111_edac.c edac: Drop __DATE__ usage 2011-04-19 00:23:22 +02:00
amd8111_edac.h edac: AMD8111 driver header file 2009-04-02 19:05:03 -07:00
amd8131_edac.c edac: Drop __DATE__ usage 2011-04-19 00:23:22 +02:00
amd8131_edac.h tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
cell_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
cpc925_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
e7xxx_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
e752x_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
edac_core.h Merge branch 'devel' 2012-07-29 21:11:05 -03:00
edac_device.c Merge branch 'devel' 2012-07-29 21:11:05 -03:00
edac_device_sysfs.c edac: Convert debugfX to edac_dbg(X, 2012-06-11 13:23:49 -03:00
edac_mc.c edac_mc: edac_mc_free() cannot assume mem_ctl_info is registered in sysfs. 2012-09-23 14:46:40 -07:00
edac_mc_sysfs.c edac: allow specifying the error count with fake_inject 2012-06-27 09:01:30 -03:00
edac_module.c edac: create top-level debugfs directory 2012-06-12 12:15:49 -03:00
edac_module.h edac: create top-level debugfs directory 2012-06-12 12:15:49 -03:00
edac_pci.c edac: Convert debugfX to edac_dbg(X, 2012-06-11 13:23:49 -03:00
edac_pci_sysfs.c edac: Convert debugfX to edac_dbg(X, 2012-06-11 13:23:49 -03:00
edac_stub.c device.h: cleanup users outside of linux/include (C files) 2012-03-11 14:27:37 -04:00
highbank_l2_edac.c edac: add support for Calxeda highbank L2 cache ecc 2012-06-27 09:01:29 -03:00
highbank_mc_edac.c edac: add support for Calxeda highbank memory controller 2012-06-27 09:00:57 -03:00
i7core_edac.c Merge branch 'devel' 2012-07-29 21:11:05 -03:00
i3000_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i3200_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i5000_edac.c edac i5000, i5400: fix pointer math in i5000_get_mc_regs() 2012-06-27 09:08:40 -03:00
i5100_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i5400_edac.c edac i5000, i5400: fix pointer math in i5000_get_mc_regs() 2012-06-27 09:08:40 -03:00
i7300_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i82443bxgx_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i82860_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i82875p_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
i82975x_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
mce_amd.c MCE, AMD: Drop too granulary family model checks 2012-04-04 15:50:11 +02:00
mce_amd.h x86/bitops: Move BIT_64() for a wider use 2012-05-23 17:16:42 +02:00
mce_amd_inj.c device.h: cleanup users outside of linux/include (C files) 2012-03-11 14:27:37 -04:00
mpc85xx_edac.c Merge branch 'devel' 2012-07-29 21:11:05 -03:00
mpc85xx_edac.h edac: Drop __DATE__ usage 2011-04-19 00:23:22 +02:00
mv64x60_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
mv64x60_edac.h edac: Drop __DATE__ usage 2011-04-19 00:23:22 +02:00
pasemi_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
ppc4xx_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
ppc4xx_edac.h edac: new ppc4xx driver module 2009-04-02 19:05:03 -07:00
r82600_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
sb_edac.c Merge branch 'devel' 2012-07-29 21:11:05 -03:00
tile_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00
x38_edac.c edac: edac_mc_handle_error(): add an error_count parameter 2012-06-12 12:15:47 -03:00