| Message ID | 20200312113006.GA20562@mwanda |
|---|---|
| State | In Next |
| Commit | 40a8d94d1cd12385645ee70d0ecae6df56a8bda8 |
| Headers | show |
| Series |
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| Related | show |
On Thu, Mar 12, 2020 at 12:30 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > We should check for a NULL pointer first before adding the offset. > Otherwise if the pointer is NULL and the offset is non-zero, it will > lead to an Oops. Thanks! > Fixes: d45048e65a59 ("lib/stackdepot.c: check depot_index before accessing the stack slab") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Alexander Potapenko <glider@google.com> > --- > lib/stackdepot.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > index da5d1880bf34..2caffc64e4c8 100644 > --- a/lib/stackdepot.c > +++ b/lib/stackdepot.c > @@ -207,18 +207,16 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, > size_t offset = parts.offset << STACK_ALLOC_ALIGN; > struct stack_record *stack; > > + *entries = NULL; > if (parts.slabindex > depot_index) { > WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n", > parts.slabindex, depot_index, handle); > - *entries = NULL; > return 0; > } > slab = stack_slabs[parts.slabindex]; > - stack = slab + offset; > - if (!stack) { > - *entries = NULL; > + if (!slab) > return 0; > - } > + stack = slab + offset; > > *entries = stack->entries; > return stack->size; > -- > 2.20.1 >
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index da5d1880bf34..2caffc64e4c8 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -207,18 +207,16 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, size_t offset = parts.offset << STACK_ALLOC_ALIGN; struct stack_record *stack; + *entries = NULL; if (parts.slabindex > depot_index) { WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n", parts.slabindex, depot_index, handle); - *entries = NULL; return 0; } slab = stack_slabs[parts.slabindex]; - stack = slab + offset; - if (!stack) { - *entries = NULL; + if (!slab) return 0; - } + stack = slab + offset; *entries = stack->entries; return stack->size;
We should check for a NULL pointer first before adding the offset. Otherwise if the pointer is NULL and the offset is non-zero, it will lead to an Oops. Fixes: d45048e65a59 ("lib/stackdepot.c: check depot_index before accessing the stack slab") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- lib/stackdepot.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)