| Message ID | 20250529-qpic-snand-avoid-mem-corruption-v2-2-2f0d13afc7d2@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | spi: spi-qpic-snand: avoid memory corruption | expand |
On 29/05/2025 18:25, Gabor Juhos wrote: > The common QPIC code does not do any boundary checking when it handles > the command elements and scatter gater list arrays of a BAM transaction, > thus it allows to access out of bounds elements in those. > > Although it is the responsibility of the given driver to allocate enough > space for all possible BAM transaction variations, however there can be > mistakes in the driver code which can lead to hidden memory corruption > issues which are hard to debug. > > This kind of problem has been observed during testing the 'spi-qpic-snand' > driver. Although the driver has been fixed with a preceding patch, but it > still makes sense to reduce the chance of having such errors again later. > > In order to prevent such errors, change the qcom_alloc_bam_transaction() > function to store the number of elements of the arrays in the > 'bam_transaction' strucutre during allocation. Also, add sanity checks to > the qcom_prep_bam_dma_desc_{cmd,data}() functions to avoid using out of > bounds indices for the arrays. > > Tested-by: Lakshmi Sowjanya D <quic_laksd@quicinc.com> # on SDX75 > Signed-off-by: Gabor Juhos <j4g8y7@gmail.com> > --- > Changes in v2: > - remove the inline qcom_err_bam_array_full() function and print the error > messages directly from the respective functions instead > - add 'Tested-by' tag from Lakshmi Sowjanya D, and remove the > "Tested with the 'spi-qpic-snand' driver only." line from the > commit message as SDX75 uses the qcom_nandc driver > - move the note about of the preferred merging order into the cover letter > --- > drivers/mtd/nand/qpic_common.c | 30 ++++++++++++++++++++++++++---- > include/linux/mtd/nand-qpic-common.h | 8 ++++++++ > 2 files changed, 34 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c > index e0ed25b5afea9b289b767cd3d9c2d7572ed52008..30f17d959300cc7448d0c2e9e2516c52655494f0 100644 > --- a/drivers/mtd/nand/qpic_common.c > +++ b/drivers/mtd/nand/qpic_common.c > @@ -57,14 +57,15 @@ qcom_alloc_bam_transaction(struct qcom_nand_controller *nandc) > bam_txn_buf += sizeof(*bam_txn); > > bam_txn->bam_ce = bam_txn_buf; > - bam_txn_buf += > - sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw; > + bam_txn->bam_ce_nitems = QPIC_PER_CW_CMD_ELEMENTS * num_cw; > + bam_txn_buf += sizeof(*bam_txn->bam_ce) * bam_txn->bam_ce_nitems; > > bam_txn->cmd_sgl = bam_txn_buf; > - bam_txn_buf += > - sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw; > + bam_txn->cmd_sgl_nitems = QPIC_PER_CW_CMD_SGL * num_cw; > + bam_txn_buf += sizeof(*bam_txn->cmd_sgl) * bam_txn->cmd_sgl_nitems; > > bam_txn->data_sgl = bam_txn_buf; > + bam_txn->data_sgl_nitems = QPIC_PER_CW_DATA_SGL * num_cw; > > init_completion(&bam_txn->txn_done); > > @@ -237,6 +238,11 @@ int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read, > struct bam_cmd_element *bam_ce_buffer; > struct bam_transaction *bam_txn = nandc->bam_txn; > > + if (bam_txn->bam_ce_pos + size > bam_txn->bam_ce_nitems) { > + dev_err(nandc->dev, "BAM %s array is full\n", "CE"); > + return -EINVAL; > + } > + > bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos]; > > /* fill the command desc */ > @@ -258,6 +264,12 @@ int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read, > > /* use the separate sgl after this command */ > if (flags & NAND_BAM_NEXT_SGL) { > + if (bam_txn->cmd_sgl_pos >= bam_txn->cmd_sgl_nitems) { > + dev_err(nandc->dev, "BAM %s array is full\n", > + "CMD sgl"); > + return -EINVAL; > + } > + > bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start]; > bam_ce_size = (bam_txn->bam_ce_pos - > bam_txn->bam_ce_start) * > @@ -297,10 +309,20 @@ int qcom_prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read, > struct bam_transaction *bam_txn = nandc->bam_txn; > > if (read) { > + if (bam_txn->rx_sgl_pos >= bam_txn->data_sgl_nitems) { > + dev_err(nandc->dev, "BAM %s array is full\n", "RX sgl"); > + return -EINVAL; > + } > + > sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos], > vaddr, size); > bam_txn->rx_sgl_pos++; > } else { > + if (bam_txn->tx_sgl_pos >= bam_txn->data_sgl_nitems) { > + dev_err(nandc->dev, "BAM %s array is full\n", "TX sgl"); > + return -EINVAL; > + } > + > sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos], > vaddr, size); > bam_txn->tx_sgl_pos++; > diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h > index cd7172e6c1bbffeee0363a14044980a72ea17723..3ca4073a496b8fd2a99112a9caefd3f110260568 100644 > --- a/include/linux/mtd/nand-qpic-common.h > +++ b/include/linux/mtd/nand-qpic-common.h > @@ -240,6 +240,9 @@ > * @last_data_desc - last DMA desc in data channel (tx/rx). > * @last_cmd_desc - last DMA desc in command channel. > * @txn_done - completion for NAND transfer. > + * @bam_ce_nitems - the number of elements in the @bam_ce array > + * @cmd_sgl_nitems - the number of elements in the @cmd_sgl array > + * @data_sgl_nitems - the number of elements in the @data_sgl array > * @bam_ce_pos - the index in bam_ce which is available for next sgl > * @bam_ce_start - the index in bam_ce which marks the start position ce > * for current sgl. It will be used for size calculation > @@ -258,6 +261,11 @@ struct bam_transaction { > struct dma_async_tx_descriptor *last_data_desc; > struct dma_async_tx_descriptor *last_cmd_desc; > struct completion txn_done; > + > + unsigned int bam_ce_nitems; > + unsigned int cmd_sgl_nitems; > + unsigned int data_sgl_nitems; > + > struct_group(bam_positions, > u32 bam_ce_pos; > u32 bam_ce_start; > > -- > 2.49.0 > > This one doesn't apply to -next deckard {~/Development/worktree/reviews/linux-next-25-05-30-daily-reviews}±(linux-next-25-05-30-daily-reviews); greetings, earthling [1.052Mb]$ ☞ b4 shazam 20250529-qpic-snand-avoid-mem-corruption-v2-0-2f0d13afc7d2@gm Grabbing thread from lore.kernel.org/all/20250529-qpic-snand-avoid-mem-corruption-v2-0-2f0d13afc7d2@gmail.com/t.mbox.gz Checking for newer revisions Grabbing search results from lore.kernel.org Analyzing 3 messages in the thread Analyzing 12 code-review messages Checking attestation on all messages, may take a moment... --- ✓ [PATCH v2 1/2] spi: spi-qpic-snand: reallocate BAM transactions ✓ [PATCH v2 2/2] mtd: nand: qpic_common: prevent out of bounds access of BAM arrays --- ✓ Signed: DKIM/gmail.com --- Total patches: 2 --- Base: using specified base-commit b00d6864a4c948529dc6ddd2df76bf175bf27c63 Applying: spi: spi-qpic-snand: reallocate BAM transactions Applying: mtd: nand: qpic_common: prevent out of bounds access of BAM arrays Patch failed at 0002 mtd: nand: qpic_common: prevent out of bounds access of BAM arrays error: patch failed: drivers/mtd/nand/qpic_common.c:237 error: drivers/mtd/nand/qpic_common.c: patch does not apply hint: Use 'git am --show-current-patch=diff' to see the failed patch hint: When you have resolved this problem, run "git am --continue". hint: If you prefer to skip this patch, run "git am --skip" instead. hint: To restore the original branch and stop patching, run "git am --abort". hint: Disable this message with "git config set advice.mergeConflict false" deckard {~/Development/worktree/reviews/linux-next-25-05-30-daily-reviews}±(linux-next-25-05-30-daily-reviews); greetings, earthling [1.052Mb]$ ☞ git-log-graph * 4ae57ce867d8f - (HEAD -> linux-next-25-05-30-daily-reviews) spi: spi-qpic-snand: reallocate BAM transactions (8 seconds ago)
2025. 05. 30. 10:56 keltezéssel, Bryan O'Donoghue írta:
...
> This one doesn't apply to -next
It is because the series is based on the SPI tree, and -next contains another
change for 'drivers/mtd/nand/qpic_common.c' which comes from the MTD tree.
It can be applied by specifying the 'M' switch for b4 shazam.
$ git reset --hard next-20250530
HEAD is now at 3a83b350b5be Add linux-next specific files for 20250530
$ b4 shazam -M 20250529-qpic-snand-avoid-mem-corruption-v2-0-2f0d13afc7d2@gmail.com
Grabbing thread from lore.kernel.org/all/20250529-qpic-snand-avoid-mem-corruption-v2-0-2f0d13afc7d2@gmail.com/t.mbox.gz
Checking for newer revisions
Grabbing search results from lore.kernel.org
Analyzing 4 messages in the thread
Analyzing 12 code-review messages
Checking attestation on all messages, may take a moment...
---
? [PATCH v2 1/2] spi: spi-qpic-snand: reallocate BAM transactions
? [PATCH v2 2/2] mtd: nand: qpic_common: prevent out of bounds access of BAM arrays
---
? Signed: DKIM/gmail.com
---
Total patches: 2
---
Base: using specified base-commit b00d6864a4c948529dc6ddd2df76bf175bf27c63
Magic: Preparing a sparse worktree
---
Applying: spi: spi-qpic-snand: reallocate BAM transactions
Applying: mtd: nand: qpic_common: prevent out of bounds access of BAM arrays
---
Fetching into FETCH_HEAD
Will exec: git merge --no-ff -F /home/juhosg/devel/linux-ipq95xx/.git/b4-cover --edit FETCH_HEAD --signoff
Press Enter to continue or Ctrl-C to abort
Auto-merging drivers/mtd/nand/qpic_common.c
Auto-merging drivers/spi/spi-qpic-snand.c
Auto-merging include/linux/mtd/nand-qpic-common.h
Merge made by the 'ort' strategy.
drivers/mtd/nand/qpic_common.c | 30 ++++++++++++++++++++++++++----
drivers/spi/spi-qpic-snand.c | 16 ++++++++++++++++
include/linux/mtd/nand-qpic-common.h | 8 ++++++++
3 files changed, 50 insertions(+), 4 deletions(-)
$
On 30/05/2025 at 13:07:35 +02, Gabor Juhos <j4g8y7@gmail.com> wrote: > 2025. 05. 30. 10:56 keltezéssel, Bryan O'Donoghue írta: > > ... > >> This one doesn't apply to -next > > It is because the series is based on the SPI tree, and -next contains another > change for 'drivers/mtd/nand/qpic_common.c' which comes from the MTD tree. > > It can be applied by specifying the 'M' switch for b4 shazam. I suggest you rebase on -rc1 (when it's out) and resend to simplify Mark's life.
diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c index e0ed25b5afea9b289b767cd3d9c2d7572ed52008..30f17d959300cc7448d0c2e9e2516c52655494f0 100644 --- a/drivers/mtd/nand/qpic_common.c +++ b/drivers/mtd/nand/qpic_common.c @@ -57,14 +57,15 @@ qcom_alloc_bam_transaction(struct qcom_nand_controller *nandc) bam_txn_buf += sizeof(*bam_txn); bam_txn->bam_ce = bam_txn_buf; - bam_txn_buf += - sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw; + bam_txn->bam_ce_nitems = QPIC_PER_CW_CMD_ELEMENTS * num_cw; + bam_txn_buf += sizeof(*bam_txn->bam_ce) * bam_txn->bam_ce_nitems; bam_txn->cmd_sgl = bam_txn_buf; - bam_txn_buf += - sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw; + bam_txn->cmd_sgl_nitems = QPIC_PER_CW_CMD_SGL * num_cw; + bam_txn_buf += sizeof(*bam_txn->cmd_sgl) * bam_txn->cmd_sgl_nitems; bam_txn->data_sgl = bam_txn_buf; + bam_txn->data_sgl_nitems = QPIC_PER_CW_DATA_SGL * num_cw; init_completion(&bam_txn->txn_done); @@ -237,6 +238,11 @@ int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read, struct bam_cmd_element *bam_ce_buffer; struct bam_transaction *bam_txn = nandc->bam_txn; + if (bam_txn->bam_ce_pos + size > bam_txn->bam_ce_nitems) { + dev_err(nandc->dev, "BAM %s array is full\n", "CE"); + return -EINVAL; + } + bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos]; /* fill the command desc */ @@ -258,6 +264,12 @@ int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read, /* use the separate sgl after this command */ if (flags & NAND_BAM_NEXT_SGL) { + if (bam_txn->cmd_sgl_pos >= bam_txn->cmd_sgl_nitems) { + dev_err(nandc->dev, "BAM %s array is full\n", + "CMD sgl"); + return -EINVAL; + } + bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start]; bam_ce_size = (bam_txn->bam_ce_pos - bam_txn->bam_ce_start) * @@ -297,10 +309,20 @@ int qcom_prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read, struct bam_transaction *bam_txn = nandc->bam_txn; if (read) { + if (bam_txn->rx_sgl_pos >= bam_txn->data_sgl_nitems) { + dev_err(nandc->dev, "BAM %s array is full\n", "RX sgl"); + return -EINVAL; + } + sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos], vaddr, size); bam_txn->rx_sgl_pos++; } else { + if (bam_txn->tx_sgl_pos >= bam_txn->data_sgl_nitems) { + dev_err(nandc->dev, "BAM %s array is full\n", "TX sgl"); + return -EINVAL; + } + sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos], vaddr, size); bam_txn->tx_sgl_pos++; diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h index cd7172e6c1bbffeee0363a14044980a72ea17723..3ca4073a496b8fd2a99112a9caefd3f110260568 100644 --- a/include/linux/mtd/nand-qpic-common.h +++ b/include/linux/mtd/nand-qpic-common.h @@ -240,6 +240,9 @@ * @last_data_desc - last DMA desc in data channel (tx/rx). * @last_cmd_desc - last DMA desc in command channel. * @txn_done - completion for NAND transfer. + * @bam_ce_nitems - the number of elements in the @bam_ce array + * @cmd_sgl_nitems - the number of elements in the @cmd_sgl array + * @data_sgl_nitems - the number of elements in the @data_sgl array * @bam_ce_pos - the index in bam_ce which is available for next sgl * @bam_ce_start - the index in bam_ce which marks the start position ce * for current sgl. It will be used for size calculation @@ -258,6 +261,11 @@ struct bam_transaction { struct dma_async_tx_descriptor *last_data_desc; struct dma_async_tx_descriptor *last_cmd_desc; struct completion txn_done; + + unsigned int bam_ce_nitems; + unsigned int cmd_sgl_nitems; + unsigned int data_sgl_nitems; + struct_group(bam_positions, u32 bam_ce_pos; u32 bam_ce_start;
The common QPIC code does not do any boundary checking when it handles the command elements and scatter gater list arrays of a BAM transaction, thus it allows to access out of bounds elements in those. Although it is the responsibility of the given driver to allocate enough space for all possible BAM transaction variations, however there can be mistakes in the driver code which can lead to hidden memory corruption issues which are hard to debug. This kind of problem has been observed during testing the 'spi-qpic-snand' driver. Although the driver has been fixed with a preceding patch, but it still makes sense to reduce the chance of having such errors again later. In order to prevent such errors, change the qcom_alloc_bam_transaction() function to store the number of elements of the arrays in the 'bam_transaction' strucutre during allocation. Also, add sanity checks to the qcom_prep_bam_dma_desc_{cmd,data}() functions to avoid using out of bounds indices for the arrays. Tested-by: Lakshmi Sowjanya D <quic_laksd@quicinc.com> # on SDX75 Signed-off-by: Gabor Juhos <j4g8y7@gmail.com> --- Changes in v2: - remove the inline qcom_err_bam_array_full() function and print the error messages directly from the respective functions instead - add 'Tested-by' tag from Lakshmi Sowjanya D, and remove the "Tested with the 'spi-qpic-snand' driver only." line from the commit message as SDX75 uses the qcom_nandc driver - move the note about of the preferred merging order into the cover letter --- drivers/mtd/nand/qpic_common.c | 30 ++++++++++++++++++++++++++---- include/linux/mtd/nand-qpic-common.h | 8 ++++++++ 2 files changed, 34 insertions(+), 4 deletions(-)