livepatch: Fix NULL pointer dereference in klp_find_func()

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A NULL old_name in a newly loaded livepatch's function entry causes a
NULL pointer dereference in strcmp():

  klp_init_patch()
    klp_add_nops()
      klp_find_func()
        strcmp(old_func->old_name, func->old_name)

Add klp_check_patch() at the beginning of klp_enable_patch() to reject
patches with NULL old_name before they reach this code path.

Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/live-patching/20260529040130.95A9C1F00893@smtp.kernel.org/
Suggested-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/20260628114635.33572-1-laoar.shao@gmail.com
Signed-off-by: Petr Mladek <pmladek@suse.com>

...

This commit is contained in:

Yafang Shao 2026-06-28 19:46:35 +08:00 • committed by Petr Mladek

parent 0839c8963b

commit 1a38fd13c3

1 changed files with 22 additions and 12 deletions

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kernel/livepatch/core.c

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