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| author |   Borislav Petkov <bp@suse.de> | 2020-09-11 12:55:55 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-15 09:41:28 +0200 |
| commit | cd8100f1f3be406a4e0e122e7307ac0fca6d57cc (patch) | |
| tree | 192fa03cb02048671878914ffd257d56e2b0bc72 /drivers/edac | |
| parent | Linux 5.9-rc5 (diff) | |
| download | linux-dev-cd8100f1f3be406a4e0e122e7307ac0fca6d57cc.tar.xz linux-dev-cd8100f1f3be406a4e0e122e7307ac0fca6d57cc.zip | |
EDAC/ghes: Clear scanned data on unload
Commit
b972fdba8665 ("EDAC/ghes: Fix NULL pointer dereference in ghes_edac_register()")
didn't clear all the information from the scanned system and, more
specifically, left ghes_hw.num_dimms to its previous value. On a
second load (CONFIG_DEBUG_TEST_DRIVER_REMOVE=y), the driver would use
the leftover num_dimms value which is not 0 and thus the 0 check in
enumerate_dimms() will get bypassed and it would go directly to the
pointer deref:
d = &hw->dimms[hw->num_dimms];
which is, of course, NULL:
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP
CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc4+ #7
Hardware name: GIGABYTE MZ01-CE1-00/MZ01-CE1-00, BIOS F02 08/29/2018
RIP: 0010:enumerate_dimms.cold+0x7b/0x375
Reset the whole ghes_hw on driver unregister so that no stale values are
used on a second system scan.
Fixes: b972fdba8665 ("EDAC/ghes: Fix NULL pointer dereference in ghes_edac_register()")
Cc: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200911164817.GA19320@zn.tnic
Diffstat (limited to 'drivers/edac')
| -rw-r--r-- | drivers/edac/ghes_edac.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c index 54ebc8afc6b1..bf7fb9f3e117 100644 --- a/drivers/edac/ghes_edac.c +++ b/drivers/edac/ghes_edac.c @@ -632,6 +632,7 @@ void ghes_edac_unregister(struct ghes *ghes) mutex_lock(&ghes_reg_mutex); system_scanned = false; + memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc)); if (!refcount_dec_and_test(&ghes_refcount)) goto unlock; |