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authorChristian Lamparter <chunkeey@gmail.com>2018-12-23 01:31:26 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-01-16 22:03:24 +0100
commit6496715c48bd8e3b7fed265ecafe5902753898fb (patch)
treeb9f9d267ed6d739172912c8fcffdd45c3a8cb7ea
parent92995f57f3a09e08ccf99408d936725553403dc0 (diff)
mtd: rawnand: qcom: fix memory corruption that causes panic
commit 81d9bdf59092e4755fc4307c93c4589ef0fe2e0f upstream. This patch fixes a memory corruption that occurred in the qcom-nandc driver since it was converted to nand_scan(). On boot, an affected device will panic from a NPE at a weird place: | Unable to handle kernel NULL pointer dereference at virtual address 0 | pgd = (ptrval) | [00000000] *pgd=00000000 | Internal error: Oops: 80000005 [#1] SMP ARM | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.9 #0 | Hardware name: Generic DT based system | PC is at (null) | LR is at nand_block_isbad+0x90/0xa4 | pc : [<00000000>] lr : [<c0592240>] psr: 80000013 | sp : cf839d40 ip : 00000000 fp : cfae9e20 | r10: cf815810 r9 : 00000000 r8 : 00000000 | r7 : 00000000 r6 : 00000000 r5 : 00000001 r4 : cf815810 | r3 : 00000000 r2 : cfae9810 r1 : ffffffff r0 : cf815810 | Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none | Control: 10c5387d Table: 8020406a DAC: 00000051 | Process swapper/0 (pid: 1, stack limit = 0x(ptrval)) | [<c0592240>] (nand_block_isbad) from [<c0580a94>] | [<c0580a94>] (allocate_partition) from [<c05811e4>] | [<c05811e4>] (add_mtd_partitions) from [<c0581164>] | [<c0581164>] (parse_mtd_partitions) from [<c057def4>] | [<c057def4>] (mtd_device_parse_register) from [<c059d274>] | [<c059d274>] (qcom_nandc_probe) from [<c0567f00>] The problem is that the nand_scan()'s qcom_nand_attach_chip callback is updating the nandc->max_cwperpage from 1 to 4. This causes the sg_init_table of clear_bam_transaction() in the driver's qcom_nandc_block_bad() to memset much more than what was initially allocated by alloc_bam_transaction(). This patch restores the old behavior by reallocating the shared bam transaction alloc_bam_transaction() after the chip was identified, but before mtd_device_parse_register() (which is an alias for mtd_device_register() - see panic) gets called. This fixes the corruption and the driver is working again. Cc: stable@vger.kernel.org Fixes: 6a3cec64f18c ("mtd: rawnand: qcom: convert driver to nand_scan()") Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Boris Brezillon <bbrezillon@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/mtd/nand/raw/qcom_nandc.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 699d3cf49c6d..7c42a57aca1f 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -2833,6 +2833,16 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
if (ret)
return ret;
+ if (nandc->props->is_bam) {
+ free_bam_transaction(nandc);
+ nandc->bam_txn = alloc_bam_transaction(nandc);
+ if (!nandc->bam_txn) {
+ dev_err(nandc->dev,
+ "failed to allocate bam transaction\n");
+ return -ENOMEM;
+ }
+ }
+
ret = mtd_device_register(mtd, NULL, 0);
if (ret)
nand_cleanup(chip);
@@ -2847,16 +2857,6 @@ static int qcom_probe_nand_devices(struct qcom_nand_controller *nandc)
struct qcom_nand_host *host;
int ret;
- if (nandc->props->is_bam) {
- free_bam_transaction(nandc);
- nandc->bam_txn = alloc_bam_transaction(nandc);
- if (!nandc->bam_txn) {
- dev_err(nandc->dev,
- "failed to allocate bam transaction\n");
- return -ENOMEM;
- }
- }
-
for_each_available_child_of_node(dn, child) {
host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
if (!host) {