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| author |   Christian Lamparter <chunkeey@gmail.com> | 2018-12-23 01:31:26 +0100 |
|---|---|---|
| committer |   Boris Brezillon <bbrezillon@kernel.org> | 2019-01-08 12:33:24 +0100 |
| commit | 81d9bdf59092e4755fc4307c93c4589ef0fe2e0f (patch) | |
| tree | f1a4465837950a119cb1662198fb3859107d40a9 /drivers/mtd | |
| parent | mtd: Check add_mtd_device() ret code (diff) | |
| download | linux-dev-81d9bdf59092e4755fc4307c93c4589ef0fe2e0f.tar.xz linux-dev-81d9bdf59092e4755fc4307c93c4589ef0fe2e0f.zip | |
mtd: rawnand: qcom: fix memory corruption that causes panic
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>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/raw/qcom_nandc.c | 20 |
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 46c62a31fa46..920e7375084f 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) { |