In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Keep the entry count when the histogram stats allocation fails<\/p>\n
print_entries() uses n_entries both as the number of sort entries and as
\nits own return value, so the -ENOMEM it stores when the stats allocation
\nfails overwrites the count that the cleanup still needs:<\/p>\n
\tn_entries = tracing_map_sort_entries(map, …);
\n\tif (n_entries max_elts pointers and calls destroy_sort_entry(), which dereferences
\nand frees, on whatever lies past the end.<\/p>\n
Reading the hist file of a trigger with a .percent value, with that
\nallocation forced to fail:<\/p>\n
BUG: KASAN: vmalloc-out-of-bounds in tracing_map_destroy_sort_entries+0xa0\/0xb0
\n Read of size 8 at addr ffffc90000045000 by task init\/1
\n tracing_map_destroy_sort_entries+0xa0\/0xb0
\n hist_show+0x6f7\/0x1df0
\n seq_read_iter+0x2b8\/0x1190
\n vfs_read+0x176\/0xa40
\n The buggy address belongs to a 4-page vmalloc region starting at
\n ffffc90000041000 allocated at tracing_map_sort_entries+0x5c\/0xd50<\/p>\n
A few pages further the fault is fatal. The registers at the oops confirm
\nthe bound: the loop’s end pointer less the array start, over the pointer
\nsize, is 4294967284.<\/p>\n
Return the error in a separate variable and leave n_entries holding the
\ncount, the way tracing_map_sort_entries() does on its own error path.<\/p>\n
The stats block is only entered for a value carrying .percent or .graph,
\nwhich __create_val_field() has rejected since v6.3, so this cannot be
\nreached in mainline as it stands. It becomes reachable again with
\n“tracing: hist: let values keep the percent and graph modifiers”, so it
\nshould be applied first.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Keep the entry count when the histogram stats allocation fails<\/p>\n
print_entries() uses n_entries both as the number of sort <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29076","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29076","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=29076"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29076"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29076"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}