From: Mikulas Patocka Date: Thu, 9 Jul 2026 19:36:01 +0000 (+0200) Subject: dm-verity: increase sprintf buffer size X-Git-Tag: v7.2-rc3~11^2~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=88dd117c92a142253fb7a17e791773902b3babc6;p=thirdparty%2Fkernel%2Fstable.git dm-verity: increase sprintf buffer size The prefix "DM_VERITY_ERR_BLOCK_NR" is 22 chars. Add '=', one digit for type, ',', up to 20 digits for a u64 block number, and a NUL terminator: that's 46 bytes. The buffer is 42 bytes. For block numbers >= 16 decimal digits (devices larger than ~16 EB with 4K blocks), snprintf silently truncates the uevent environment variable. Signed-off-by: Mikulas Patocka Assisted-by: Claude:claude-opus-4.6 Fixes: 65ff5b7ddf05 ("dm verity: add error handling modes for corrupted blocks") Cc: stable@vger.kernel.org --- diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index adfda1fdab6a..e63a8290bd3a 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -26,7 +26,7 @@ #define DM_MSG_PREFIX "verity" -#define DM_VERITY_ENV_LENGTH 42 +#define DM_VERITY_ENV_LENGTH 46 #define DM_VERITY_ENV_VAR_NAME "DM_VERITY_ERR_BLOCK_NR" #define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144