From: Toshi Kani toshi.kani@hpe.com
commit 5e2805d5379619c4a2e3ae4994e73b36439f4bad upstream.
The commit
cb51a371d08e ("EDAC/ghes: Setup DIMM label from DMI and use it in error reports")
enforced that both the bank and device strings passed to dimm_setup_label() are not NULL.
However, there are BIOSes, for example on a
HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/15/2019
which don't populate both strings:
Handle 0x0020, DMI type 17, 84 bytes Memory Device Array Handle: 0x0013 Error Information Handle: Not Provided Total Width: 72 bits Data Width: 64 bits Size: 32 GB Form Factor: DIMM Set: None Locator: PROC 1 DIMM 1 <===== device Bank Locator: Not Specified <===== bank
This results in a buffer overflow because ghes_edac_register() calls strlen() on an uninitialized label, which had non-zero values left over from krealloc_array():
detected buffer overflow in __fortify_strlen ------------[ cut here ]------------ kernel BUG at lib/string_helpers.c:983! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 1 Comm: swapper/0 Tainted: G I 5.18.6-200.fc36.x86_64 #1 Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 03/15/2019 RIP: 0010:fortify_panic ... Call Trace: <TASK> ghes_edac_register.cold ghes_probe platform_probe really_probe __driver_probe_device driver_probe_device __driver_attach ? __device_attach_driver bus_for_each_dev bus_add_driver driver_register acpi_ghes_init acpi_init ? acpi_sleep_proc_init do_one_initcall
The label contains garbage because the commit in Fixes reallocs the DIMMs array while scanning the system but doesn't clear the newly allocated memory.
Change dimm_setup_label() to always initialize the label to fix the issue. Set it to the empty string in case BIOS does not provide both bank and device so that ghes_edac_register() can keep the default label given by edac_mc_alloc_dimms().
[ bp: Rewrite commit message. ]
Fixes: b9cae27728d1f ("EDAC/ghes: Scan the system once on driver init") Co-developed-by: Robert Richter rric@kernel.org Signed-off-by: Robert Richter rric@kernel.org Signed-off-by: Toshi Kani toshi.kani@hpe.com Signed-off-by: Borislav Petkov bp@suse.de Tested-by: Robert Elliott elliott@hpe.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220719220124.760359-1-toshi.kani@hpe.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/edac/ghes_edac.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/edac/ghes_edac.c +++ b/drivers/edac/ghes_edac.c @@ -101,9 +101,14 @@ static void dimm_setup_label(struct dimm
dmi_memdev_name(handle, &bank, &device);
- /* both strings must be non-zero */ - if (bank && *bank && device && *device) - snprintf(dimm->label, sizeof(dimm->label), "%s %s", bank, device); + /* + * Set to a NULL string when both bank and device are zero. In this case, + * the label assigned by default will be preserved. + */ + snprintf(dimm->label, sizeof(dimm->label), "%s%s%s", + (bank && *bank) ? bank : "", + (bank && *bank && device && *device) ? " " : "", + (device && *device) ? device : ""); }
static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)