Kernel NULL pointer dereference when ACPI SAR table isn't implemented well.
Fix the error code of return to mark the ACPI SAR table as invalid.
[ 5.077128] mt7921e 0000:06:00.0: sar cnt = 0
[ 5.077381] BUG: kernel NULL pointer dereference, address:
0000000000000004
[ 5.077630] #PF: supervisor read access in kernel mode
[ 5.077883] #PF: error_code(0x0000) - not-present page
[ 5.078138] PGD 0 P4D 0
[ 5.078398] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 5.079202] RIP: 0010:mt7921_init_acpi_sar+0x106/0x220
[mt7921_common]
...
[ 5.080786] Call Trace:
[ 5.080786] <TASK>
[ 5.080786] mt7921_register_device+0x37d/0x490 [mt7921_common]
[ 5.080786] mt7921_pci_probe.part.0+0x2ee/0x310 [mt7921e]
[ 5.080786] mt7921_pci_probe+0x52/0x70 [mt7921e]
[ 5.080786] local_pci_probe+0x47/0x90
[ 5.080786] pci_call_probe+0x55/0x190
[ 5.080786] pci_device_probe+0x84/0x120
Fixes: f965333e491e ("mt76: mt7921: introduce ACPI SAR support")
Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c
index 47e034a9b003..ed9241d4aa64 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c
@@ -33,14 +33,17 @@ mt7921_acpi_read(struct mt7921_dev *dev, u8 *method, u8 **tbl, u32 *len)
sar_root->package.elements[0].type != ACPI_TYPE_INTEGER) {
dev_err(mdev->dev, "sar cnt = %d\n",
sar_root->package.count);
+ ret = -EINVAL;
goto free;
}
if (!*tbl) {
*tbl = devm_kzalloc(mdev->dev, sar_root->package.count,
GFP_KERNEL);
- if (!*tbl)
+ if (!*tbl) {
+ ret = -ENOMEM;
goto free;
+ }
}
if (len)
*len = sar_root->package.count;
@@ -52,9 +55,9 @@ mt7921_acpi_read(struct mt7921_dev *dev, u8 *method, u8 **tbl, u32 *len)
break;
*(*tbl + i) = (u8)sar_unit->integer.value;
}
-free:
ret = (i == sar_root->package.count) ? 0 : -EINVAL;
+free:
kfree(sar_root);
return ret;
--
2.34.1
