wifi: p54: Annotate struct p54_cal_database with __counted_by
PATCH 1/1 wifi: p54: Annotate struct p54_cal_database with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct p54_cal_database.
--- drivers/net/wireless/intersil/p54/p54.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/net/wireless/intersil/p54/p54.h +1 -1
@@ -126,7 +126,7 @@ struct p54_cal_database {size_t entry_size;size_t offset;size_t len; -u8 data[]; + u8 data[] __counted_by(entries); };#define EEPROM_READBACK_LEN 0x3fc
Signature · 1 line
2.34.1
Quoted 8 lines · Kees Cook
Prepare for the coming implementation by GCC and Clang of the
__counted_byattribute. Flexible array members annotated with__counted_bycan have their accesses bounds-checked at run-time viaCONFIG_UBSAN_BOUNDS(for array indexing) andCONFIG_FORTIFY_SOURCE(for strcpy/memcpy-family functions).As found with Coccinelle[1], add
__counted_byfor structp54_cal_database.
Quoted 7 lines
Cc Christian Lamparter <[email protected]>Cc Kalle Valo <[email protected]>Cc "Gustavo A. R. Silva" <[email protected]>Signed-off-by Kees Cook <[email protected]>
Thanks!
Signature · 1 line
Gustavo
Quoted 17 lines
--- drivers/net/wireless/intersil/p54/p54.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/net/wireless/intersil/p54/p54.h +1
-1@@ -126,7 +126,7 @@ struct p54_cal_database {size_t entry_size;size_t offset;size_t len; -u8 data[]; + u8 data[] __counted_by(entries); };#define EEPROM_READBACK_LEN 0x3fc
Hi,
I randomly peeked at this patch. Unfortunately, I am not familiar with the actual p54 code.
Quoted 25 lines · Kees Cook
Prepare for the coming implementation by GCC and Clang of the
__counted_byattribute. Flexible array members annotated with__counted_bycan have their accesses bounds-checked at run-time viaCONFIG_UBSAN_BOUNDS(for array indexing) andCONFIG_FORTIFY_SOURCE(for strcpy/memcpy-family functions).As found with Coccinelle[1], add
__counted_byfor structp54_cal_database.Cc Christian Lamparter <[email protected]>Cc Kalle Valo <[email protected]>Cc "Gustavo A. R. Silva" <[email protected]>Signed-off-by Kees Cook <[email protected]>--- drivers/net/wireless/intersil/p54/p54.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/net/wireless/intersil/p54/p54.h +0
-0
drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 129
Quoted 5 lines
drivers/net/wireless/intersil/p54/p54.h +1
-1@@ -126,7 +126,7 @@ struct p54_cal_database {size_t entry_size;size_t offset;size_t len; -u8 data[]; + u8 data[] __counted_by(entries);
This looks incorrect - I think you want __counted_by(len)? The presence of entry_size made me suspicious.
drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 130
Quoted 1 line
drivers/net/wireless/intersil/p54/p54.h +0
-0};
This is the function that creates struct p54_cal_database:
static struct p54_cal_database *p54_convert_db(struct pda_custom_wrapper *src,
size_t total_len)
{
struct p54_cal_database *dst;
size_t payload_len, entries, entry_size, offset;
payload_len = le16_to_cpu(src->len);
entries = le16_to_cpu(src->entries);
entry_size = le16_to_cpu(src->entry_size);
offset = le16_to_cpu(src->offset);
if (((entries * entry_size + offset) != payload_len) ||
(payload_len + sizeof(*src) != total_len))
return NULL;
dst = kmalloc(sizeof(*dst) + payload_len, GFP_KERNEL);
if (!dst)
return NULL;
dst->entries = entries;
dst->entry_size = entry_size;
dst->offset = offset;
dst->len = payload_len;
memcpy(dst->data, src->data, payload_len);
return dst;
}You can see that kmalloc is performed with sizeof(*dst) + payload_len, and payload_len is assigned to ->len.
I don't read Coccinelle, but, if this patch was auto-generated, I wonder if the script has an error.
Regards,
Jason
Quoted 26 lines · Jason Andryuk
Hi,
I randomly peeked at this patch. Unfortunately, I am not familiar with the actual p54 code.
Quoted 20 lines · Kees Cook
Prepare for the coming implementation by GCC and Clang of the
__counted_byattribute. Flexible array members annotated with__counted_bycan have their accesses bounds-checked at run-time viaCONFIG_UBSAN_BOUNDS(for array indexing) andCONFIG_FORTIFY_SOURCE(for strcpy/memcpy-family functions).As found with Coccinelle[1], add
__counted_byfor structp54_cal_database.Cc Christian Lamparter <[email protected]>Cc Kalle Valo <[email protected]>Cc "Gustavo A. R. Silva" <[email protected]>Signed-off-by Kees Cook <[email protected]>--- drivers/net/wireless/intersil/p54/p54.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Quoted 12 lines
drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 129
Quoted 10 lines
drivers/net/wireless/intersil/p54/p54.h +1
-1@@ -126,7 +126,7 @@ struct p54_cal_database {size_t entry_size;size_t offset;size_t len; -u8 data[]; + u8 data[] __counted_by(entries);This looks incorrect - I think you want
__counted_by(len)? The
I think you're right. More comments below...
Quoted 33 lines
presence of
entry_sizemade me suspicious.drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 130
Quoted 1 line
drivers/net/wireless/intersil/p54/p54.h +0
-0};This is the function that creates struct
p54_cal_database:static struct
p54_cal_database*p54_convert_db(structpda_custom_wrapper*src,
size_ttotal_len){ struct p54_cal_database *dst; size_t payload_len, entries, entry_size, offset; payload_len = le16_to_cpu(src->len); entries = le16_to_cpu(src->entries); entry_size = le16_to_cpu(src->entry_size); offset = le16_to_cpu(src->offset); if (((entries * entry_size + offset) != payload_len) || (payload_len + sizeof(*src) != total_len)) return NULL; dst = kmalloc(sizeof(*dst) + payload_len, GFP_KERNEL); if (!dst) return NULL; dst->entries = entries; dst->entry_size = entry_size; dst->offset = offset; dst->len = payload_len; memcpy(dst->data, src->data, payload_len); return dst; }
Quoted 2 lines
You can see that kmalloc is performed with
sizeof(*dst) + payload_len, andpayload_lenis assigned to ->len.
This should be changed to:
- dst = kmalloc(sizeof(*dst) + payload_len, GFP_KERNEL);
+ dst = kmalloc(struct_size(dst, data, payload_len), GFP_KERNEL);
Quoted 3 lines
I don't read Coccinelle, but, if this patch was auto-generated, I wonder if the script has an error.
With the struct_size() change, the Coccinelle script should be able to generate a correct patch for this.
--
Gustavo
Quoted 71 lines · Jason Andryuk
Hi,
I randomly peeked at this patch. Unfortunately, I am not familiar with the actual p54 code.
Quoted 25 lines · Kees Cook
Prepare for the coming implementation by GCC and Clang of the
__counted_byattribute. Flexible array members annotated with__counted_bycan have their accesses bounds-checked at run-time viaCONFIG_UBSAN_BOUNDS(for array indexing) andCONFIG_FORTIFY_SOURCE(for strcpy/memcpy-family functions).As found with Coccinelle[1], add
__counted_byfor structp54_cal_database.Cc Christian Lamparter <[email protected]>Cc Kalle Valo <[email protected]>Cc "Gustavo A. R. Silva" <[email protected]>Signed-off-by Kees Cook <[email protected]>--- drivers/net/wireless/intersil/p54/p54.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/net/wireless/intersil/p54/p54.h +0
-0drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 129
Quoted 5 lines
drivers/net/wireless/intersil/p54/p54.h +1
-1@@ -126,7 +126,7 @@ struct p54_cal_database {size_t entry_size;size_t offset;size_t len; -u8 data[]; + u8 data[] __counted_by(entries);This looks incorrect - I think you want
__counted_by(len)? The presence ofentry_sizemade me suspicious.drivers/net/wireless/intersil/p54/p54.h struct p54_cal_database { · line 130
Quoted 1 line
drivers/net/wireless/intersil/p54/p54.h +0
-0};This is the function that creates struct
p54_cal_database:static struct
p54_cal_database*p54_convert_db(structpda_custom_wrapper*src,
size_ttotal_len){ struct p54_cal_database *dst; size_t payload_len, entries, entry_size, offset; payload_len = le16_to_cpu(src->len); entries = le16_to_cpu(src->entries); entry_size = le16_to_cpu(src->entry_size); offset = le16_to_cpu(src->offset); if (((entries * entry_size + offset) != payload_len) || (payload_len + sizeof(*src) != total_len)) return NULL; dst = kmalloc(sizeof(*dst) + payload_len, GFP_KERNEL); if (!dst) return NULL; dst->entries = entries; dst->entry_size = entry_size; dst->offset = offset; dst->len = payload_len; memcpy(dst->data, src->data, payload_len); return dst; }
Quoted 2 lines
You can see that kmalloc is performed with
sizeof(*dst) + payload_len, andpayload_lenis assigned to ->len.
Agreed!
Quoted 2 lines
I don't read Coccinelle, but, if this patch was auto-generated, I wonder if the script has an error.
Yeah, I'm not sure which part went wrong. I will investigate. Thanks for catching this!
Signature · 1 line
Kees Cook
Quoted 29 lines · Jason Andryuk
This is the function that creates struct
p54_cal_database:static struct
p54_cal_database*p54_convert_db(structpda_custom_wrapper*src,
size_ttotal_len){ struct p54_cal_database *dst; size_t payload_len, entries, entry_size, offset; payload_len = le16_to_cpu(src->len); entries = le16_to_cpu(src->entries); entry_size = le16_to_cpu(src->entry_size); offset = le16_to_cpu(src->offset); if (((entries * entry_size + offset) != payload_len) || (payload_len + sizeof(*src) != total_len)) return NULL; dst = kmalloc(sizeof(*dst) + payload_len, GFP_KERNEL); if (!dst) return NULL; dst->entries = entries; dst->entry_size = entry_size; dst->offset = offset; dst->len = payload_len; memcpy(dst->data, src->data, payload_len); return dst; }
Quoted 5 lines
You can see that kmalloc is performed with
sizeof(*dst) + payload_len, andpayload_lenis assigned to ->len.I don't read Coccinelle, but, if this patch was auto-generated, I wonder if the script has an error.
It seems that my Coccinelle script got confused by this:
p54_convert_output_limits():
priv->output_limit = kmalloc(data[1] *
sizeof(struct pda_channel_output_limit) +
sizeof(*priv->output_limit), GFP_KERNEL);
...
priv->output_limit->entry_size =
sizeof(struct pda_channel_output_limit);
priv->output_limit->len = priv->output_limit->entry_size *
priv->output_limit->entries +
priv->output_limit->offset;It thought "sizeof(struct pda_channel_output_limit)" was the element count, since it wasn't able to identify the array member here.
Regardless, I've sent a v2 now. :)
Signature · 1 line
Kees Cook