On Mon, Apr 18, 2022 at 10:49:01AM +0530, Md Sadre Alam wrote:
> This patch fixes a memory corruption that occurred in the
> nand_scan() path for Hynix nand device.
>
> On boot, for Hynix nand device will panic at a weird place:
> | Unable to handle kernel NULL pointer dereference at virtual
> address 00000070
> | [00000070] *pgd=00000000
> | Internal error: Oops: 5 [#1] PREEMPT SMP ARM
> | Modules linked in:
> | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
> #38
> | Hardware name: Generic DT based system
> | PC is at nandc_set_reg+0x8/0x1c
> | LR is at qcom_nandc_command+0x20c/0x5d0
> | pc : [<c088b74c>] lr : [<c088d9c8>] psr: 00000113
> | sp : c14adc50 ip : c14ee208 fp : c0cc970c
> | r10: 000000a3 r9 : 00000000 r8 : 00000040
> | r7 : c16f6a00 r6 : 00000090 r5 : 00000004 r4 :c14ee040
> | r3 : 00000000 r2 : 0000000b r1 : 00000000 r0 :c14ee040
> | Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
> | Control: 10c5387d Table: 8020406a DAC: 00000051
> | Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
> 64 size 2048
> | Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
> | nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
> | qcom_nandc_command from nand_readid_op+0x198/0x1e8
> | nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
> | hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
> | hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
> | nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
> | qcom_nandc_probe from platform_probe+0x58/0xac
>
> 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_command() to memset much more than what was initially
> allocated by alloc_bam_transaction().
>
> This patch will update nandc->max_cwperpage 1 to 4 after nand_scan()
> returns, and remove updating nandc->max_cwperpage from
> qcom_nand_attach_chip call back.
The above statement is still wrong.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 6a3cec64f18c ("mtd: rawnand: qcom: convert driver to nand_scan()")
> Reported-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
> Signed-off-by: Md Sadre Alam <quic_mdalam@xxxxxxxxxxx>
> Signed-off-by: Sricharan R <quic_srichara@xxxxxxxxxxx>
> ---
> [V3]
> * Updated commit message Fixes, Cc, Reported-by
Missing the previous changelogs.
Thanks,
Mani
>
> drivers/mtd/nand/raw/qcom_nandc.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 1a77542..048b255 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2651,10 +2651,23 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
> ecc->engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
>
> mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
> + /* Free the initially allocated BAM transaction for reading the ONFI params */
> + if (nandc->props->is_bam)
> + free_bam_transaction(nandc);
>
> nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
> cwperpage);
>
> + /* Now allocate the BAM transaction based on updated max_cwperpage */
> + if (nandc->props->is_bam) {
> + nandc->bam_txn = alloc_bam_transaction(nandc);
> + if (!nandc->bam_txn) {
> + dev_err(nandc->dev,
> + "failed to allocate bam transaction\n");
> + return -ENOMEM;
> + }
> + }
> +
> /*
> * DATA_UD_BYTES varies based on whether the read/write command protects
> * spare data with ECC too. We protect spare data by default, so we set
> @@ -2955,17 +2968,6 @@ 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");
> - nand_cleanup(chip);
> - return -ENOMEM;
> - }
> - }
> -
> ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0);
> if (ret)
> nand_cleanup(chip);
> --
> 2.7.4
>
