From 1da36bedeab0a259d87e782b2adf34c18042a7cd Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Tue, 25 Feb 2020 09:26:08 +0300 Subject: [PATCH] tpm: tpm1_bios_measurements_next should increase position index commit d7a47b96ed1102551eb7325f97937e276fb91045 upstream. If .next function does not change position index, following .show function will repeat output related to current position index. In case of /sys/kernel/security/tpm0/ascii_bios_measurements and binary_bios_measurements: 1) read after lseek beyound end of file generates whole last line. 2) read after lseek to middle of last line generates expected end of last line and unexpected whole last line once again. Cc: stable@vger.kernel.org # 4.19.x Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/eventlog/tpm1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/eventlog/tpm1.c b/drivers/char/tpm/eventlog/tpm1.c index 58c84784ba25c..a4621c83e2bf7 100644 --- a/drivers/char/tpm/eventlog/tpm1.c +++ b/drivers/char/tpm/eventlog/tpm1.c @@ -129,6 +129,7 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v, u32 converted_event_size; u32 converted_event_type; + (*pos)++; converted_event_size = do_endian_conversion(event->event_size); v += sizeof(struct tcpa_event) + converted_event_size; @@ -146,7 +147,6 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v, ((v + sizeof(struct tcpa_event) + converted_event_size) >= limit)) return NULL; - (*pos)++; return v; } -- 2.47.3