4.19-stable review patch. If anyone has any objections, please let me know.
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From: Christophe JAILLET christophe.jaillet@wanadoo.fr
[ Upstream commit 4f41d30cd6dc865c3cbc1a852372321eba6d4e4c ]
When appending "[defcmd]" to 'kdb_prompt_str', the size of the string already in the buffer should be taken into account.
An option could be to switch from strncat() to strlcat() which does the correct test to avoid such an overflow.
However, this actually looks as dead code, because 'defcmd_in_progress' can't be true here. See a more detailed explanation at [1].
[1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j...
Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Christophe JAILLET christophe.jaillet@wanadoo.fr Reviewed-by: Douglas Anderson dianders@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/debug/kdb/kdb_main.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 8f31d472384f..7f78657dfa00 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1309,8 +1309,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs, /* PROMPT can only be set if we have MEM_READ permission. */ snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"), raw_smp_processor_id()); - if (defcmd_in_progress) - strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
/* * Fetch command from keyboard