mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-12-29 17:25:38 +00:00
scripts/kallsyms.c: fix potential segfault
Description: This bug hardly appears during real kernel compiling, because the vmlinux symbols table is huge. But we can still catch it under strict condition , as follows. $ echo "c101b97b T do_fork" | ./scripts/kallsyms --all-symbols #include <asm/types.h> ...... ...... .globl kallsyms_token_table ALGN kallsyms_token_table: Segmentation fault (core dumped) $ If symbols table is small, all entries in token_profit[0x10000] may decrease to 0 after several calls of compress_symbols() in optimize_result(). In that case, find_best_token() always return 0 and best_table[i] is set to "\0\0" and best_table_len[i] is set to 2. As a result, expand_symbol(best_table[0]="\0\0", best_table_len[0]=2, buf) in write_src() will run in infinite recursion until stack overflows, causing segfault. This patch checks the find_best_token() return value. If all entries in token_profit[0x10000] become 0 according to return value, it breaks the loop in optimize_result(). And expand_symbol() works well when best_table_len[i] is 0. Signed-off-by: Xiaochen Wang <wangxiaochen0@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
This commit is contained in:
parent
153f011470
commit
e0a04b11e4
@ -500,6 +500,8 @@ static void optimize_result(void)
|
||||
|
||||
/* find the token with the breates profit value */
|
||||
best = find_best_token();
|
||||
if (token_profit[best] == 0)
|
||||
break;
|
||||
|
||||
/* place it in the "best" table */
|
||||
best_table_len[i] = 2;
|
||||
|
Loading…
Reference in New Issue
Block a user