CVE-2026-97920

Status: UPDATED  |  Advisory ID: CVE-2026-97920

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

tracing: Keep the entry count when the histogram stats allocation fails

print_entries() uses n_entries both as the number of sort entries and as

its own return value, so the -ENOMEM it stores when the stats allocation

fails overwrites the count that the cleanup still needs:

n_entries = tracing_map_sort_entries(map, ...);

if (n_entries < 0)

return n_entries;

...

if (!stats) {

n_entries = -ENOMEM;

goto out;

}

...

out:

tracing_map_destroy_sort_entries(sort_entries, n_entries);

tracing_map_destroy_sort_entries() takes an unsigned int and loops up to

it, so -ENOMEM arrives as 4294967284. It walks an array of at most

map->max_elts pointers and calls destroy_sort_entry(), which dereferences

and frees, on whatever lies past the end.

Reading the hist file of a trigger with a .percent value, with that

allocation forced to fail:

BUG: KASAN: vmalloc-out-of-bounds in tracing_map_destroy_sort_entries+0xa0/0xb0

Read of size 8 at addr ffffc90000045000 by task init/1

tracing_map_destroy_sort_entries+0xa0/0xb0

hist_show+0x6f7/0x1df0

seq_read_iter+0x2b8/0x1190

vfs_read+0x176/0xa40

The buggy address belongs to a 4-page vmalloc region starting at

ffffc90000041000 allocated at tracing_map_sort_entries+0x5c/0xd50

A few pages further the fault is fatal. The registers at the oops confirm

the bound: the loop's end pointer less the array start, over the pointer

size, is 4294967284.

Return the error in a separate variable and leave n_entries holding the

count, the way tracing_map_sort_entries() does on its own error path.

The stats block is only entered for a value carrying .percent or .graph,

which __create_val_field() has rejected since v6.3, so this cannot be

reached in mainline as it stands. It becomes reachable again with

"tracing: hist: let values keep the percent and graph modifiers", so it

should be applied first. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References