The cell sysfs attribute should not provide more access to the nvmem data than the main attribute itself. For example if nvme_config::root_only was set, the cell attribute would still provide read access to everybody.
Mask out permissions not available on the main attribute.
Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- This was also discussed as part of "[PATCH] nvmem: core: add sysfs cell write support" [0]. But there haven't been updates to that patch and this is arguably a standalone bugfix.
[0] https://lore.kernel.org/lkml/20240223154129.1902905-1-m.felsch@pengutronix.d... --- drivers/nvmem/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index e1ec3b7200d7..acfea1e56849 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -463,7 +463,7 @@ static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem) "%s@%x,%x", entry->name, entry->offset, entry->bit_offset); - attrs[i].attr.mode = 0444; + attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem); attrs[i].size = entry->bytes; attrs[i].read = &nvmem_cell_attr_read; attrs[i].private = entry;
--- base-commit: 92e5605a199efbaee59fb19e15d6cc2103a04ec2 change-id: 20240619-nvmem-cell-sysfs-perm-156fde0d7460
Best regards,
On 19/06/2024 19:09, Thomas Weißschuh wrote:
The cell sysfs attribute should not provide more access to the nvmem data than the main attribute itself. For example if nvme_config::root_only was set, the cell attribute would still provide read access to everybody.
Mask out permissions not available on the main attribute.
Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh linux@weissschuh.net
This was also discussed as part of "[PATCH] nvmem: core: add sysfs cell write support" [0]. But there haven't been updates to that patch and this is arguably a standalone bugfix.
[0] https://lore.kernel.org/lkml/20240223154129.1902905-1-m.felsch@pengutronix.d...
drivers/nvmem/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index e1ec3b7200d7..acfea1e56849 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -463,7 +463,7 @@ static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem) "%s@%x,%x", entry->name, entry->offset, entry->bit_offset);
attrs[i].attr.mode = 0444;
attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem);
Why not just attrs[i].attr.mode = nvmem_bin_attr_get_umode(nvmem); ?
--srini
attrs[i].size = entry->bytes; attrs[i].read = &nvmem_cell_attr_read; attrs[i].private = entry;
base-commit: 92e5605a199efbaee59fb19e15d6cc2103a04ec2 change-id: 20240619-nvmem-cell-sysfs-perm-156fde0d7460
Best regards,
Jun 22, 2024 12:11:04 Srinivas Kandagatla srinivas.kandagatla@linaro.org:
On 19/06/2024 19:09, Thomas Weißschuh wrote:
The cell sysfs attribute should not provide more access to the nvmem data than the main attribute itself. For example if nvme_config::root_only was set, the cell attribute would still provide read access to everybody. Mask out permissions not available on the main attribute. Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh linux@weissschuh.net
This was also discussed as part of "[PATCH] nvmem: core: add sysfs cell write support" [0]. But there haven't been updates to that patch and this is arguably a standalone bugfix. [0] https://lore.kernel.org/lkml/20240223154129.1902905-1-m.felsch@pengutronix.d...
drivers/nvmem/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index e1ec3b7200d7..acfea1e56849 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -463,7 +463,7 @@ static int nvmem_populate_sysfs_cells(struct nvmem_device *nvmem) "%s@%x,%x", entry->name, entry->offset, entry->bit_offset); - attrs[i].attr.mode = 0444; + attrs[i].attr.mode = 0444 & nvmem_bin_attr_get_umode(nvmem);
Why not just attrs[i].attr.mode = nvmem_bin_attr_get_umode(nvmem);
Because nvmem_bin_attr_get_umode() will include write permissions if the base nvmem device is writable.
But (for now) the cell sysfs attributes do not implement writes.
?
--srini
attrs[i].size = entry->bytes; attrs[i].read = &nvmem_cell_attr_read; attrs[i].private = entry;
base-commit: 92e5605a199efbaee59fb19e15d6cc2103a04ec2 change-id: 20240619-nvmem-cell-sysfs-perm-156fde0d7460 Best regards,
On Wed, 19 Jun 2024 20:09:00 +0200, Thomas Weißschuh wrote:
The cell sysfs attribute should not provide more access to the nvmem data than the main attribute itself. For example if nvme_config::root_only was set, the cell attribute would still provide read access to everybody.
Mask out permissions not available on the main attribute.
[...]
Applied, thanks!
[1/1] nvmem: core: limit cell sysfs permissions to main attribute ones commit: 4eeb1d829b54d16ee5bbe9188e6013d424c6e859
Best regards,
linux-stable-mirror@lists.linaro.org
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Srinivas Kandagatla -
Thomas Weißschuh -
Thomas Weißschuh