6.6-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Weißschuh linux@weissschuh.net
[ Upstream commit 4d231a7df1a85c7572b67a4666cb73adb977fbf6 ]
In twos complement the most negative number can not be negated.
Fixes: b1c21e7d99cd ("tools/nolibc/stdlib: add i64toa() and u64toa()") Fixes: 66c397c4d2e1 ("tools/nolibc/stdlib: replace the ltoa() function with more efficient ones") Signed-off-by: Thomas Weißschuh linux@weissschuh.net Acked-by: Willy Tarreau w@1wt.eu Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-5-060b8a016917@weissschuh... Signed-off-by: Sasha Levin sashal@kernel.org --- tools/include/nolibc/stdlib.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h index 5be9d3c7435a8..6bf62f5048faa 100644 --- a/tools/include/nolibc/stdlib.h +++ b/tools/include/nolibc/stdlib.h @@ -274,7 +274,7 @@ int itoa_r(long in, char *buffer) int len = 0;
if (in < 0) { - in = -in; + in = -(unsigned long)in; *(ptr++) = '-'; len++; } @@ -410,7 +410,7 @@ int i64toa_r(int64_t in, char *buffer) int len = 0;
if (in < 0) { - in = -in; + in = -(uint64_t)in; *(ptr++) = '-'; len++; }