diff options
| author | Shiju Jose <shiju.jose@huawei.com> | 2020-08-27 17:04:50 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-08-27 19:04:07 +0300 |
| commit | b972fdba8665d75109ade0357739f46af6415d2a (patch) | |
| tree | ad189170d20c38c531ffbaa84f8a7c94b5fe2f70 /drivers/edac | |
| parent | d012a7190fc1fd72ed48911e77ca97ba4521bccd (diff) | |
| download | linux-b972fdba8665d75109ade0357739f46af6415d2a.tar.xz | |
EDAC/ghes: Fix NULL pointer dereference in ghes_edac_register()
After
b9cae27728d1 ("EDAC/ghes: Scan the system once on driver init")
and with CONFIG_DEBUG_TEST_DRIVER_REMOVE enabled, ghes_hw.dimms becomes
a NULL pointer after the second ->probe() (aka ghes_edac_register())
which the config option causes to be called.
This happens because the static variable which holds down whether
the system has been scanned already, doesn't get reset in
ghes_edac_unregister(). Then, on the second probe, ghes_scan_system()
doesn't get to enumerate the DIMMs, leading to ghes_hw.dimms remaining
NULL.
Clear the variable and rename it to something more descriptive so that a
second probe succeeds.
[ bp: Rewrite commit message. ]
Fixes: b9cae27728d1 ("EDAC/ghes: Scan the system once on driver init")
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200827140450.1620-1-shiju.jose@huawei.com
Diffstat (limited to 'drivers/edac')
| -rw-r--r-- | drivers/edac/ghes_edac.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c index da60c29468a7..54ebc8afc6b1 100644 --- a/drivers/edac/ghes_edac.c +++ b/drivers/edac/ghes_edac.c @@ -55,6 +55,8 @@ static DEFINE_SPINLOCK(ghes_lock); static bool __read_mostly force_load; module_param(force_load, bool, 0); +static bool system_scanned; + /* Memory Device - Type 17 of SMBIOS spec */ struct memdev_dmi_entry { u8 type; @@ -225,14 +227,12 @@ static void enumerate_dimms(const struct dmi_header *dh, void *arg) static void ghes_scan_system(void) { - static bool scanned; - - if (scanned) + if (system_scanned) return; dmi_walk(enumerate_dimms, &ghes_hw); - scanned = true; + system_scanned = true; } void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err) @@ -631,6 +631,8 @@ void ghes_edac_unregister(struct ghes *ghes) mutex_lock(&ghes_reg_mutex); + system_scanned = false; + if (!refcount_dec_and_test(&ghes_refcount)) goto unlock; |