nvpair: Use flexible array member for nvpair name strings

Coverity reported possible out-of-bounds reads from doing `((char
*)(nvp) + sizeof (nvpair_t))` to get the nvpair name string. These were
initially marked as false positives, but since we are now using C99
flexible array members elsewhere, we could use them here too as cleanup
to make the code easier to understand.

Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Reported-by: Coverity (CID-977165)
Reported-by: Coverity (CID-1524109)
Reported-by: Coverity (CID-1524642)
Closes #14612
This commit is contained in:
Richard Yao 2023-03-11 13:39:24 -05:00 committed by Brian Behlendorf
parent d1807f168e
commit dbfc622345

View File

@ -76,7 +76,7 @@ typedef struct nvpair {
int16_t nvp_reserve; /* not used */
int32_t nvp_value_elem; /* number of elements for array types */
data_type_t nvp_type; /* type of value */
/* name string */
char nvp_name[]; /* name string */
/* aligned ptr array for string arrays */
/* aligned array of data for value */
} nvpair_t;
@ -109,7 +109,7 @@ typedef struct nvlist {
#define NV_ALIGN4(x) (((x) + 3) & ~3)
#define NVP_SIZE(nvp) ((nvp)->nvp_size)
#define NVP_NAME(nvp) ((char *)(nvp) + sizeof (nvpair_t))
#define NVP_NAME(nvp) ((nvp)->nvp_name)
#define NVP_TYPE(nvp) ((nvp)->nvp_type)
#define NVP_NELEM(nvp) ((nvp)->nvp_value_elem)
#define NVP_VALUE(nvp) ((char *)(nvp) + NV_ALIGN(sizeof (nvpair_t) \