From a4c13a7469b60c7363d07f8b5224eb244571a107 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 eccab63068df08a89fe8089fd92355bca426c34a 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: 46cb04d471b6 ("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 739b1d9d16b64..2c96977ad080a 100644 --- a/drivers/char/tpm/eventlog/tpm1.c +++ b/drivers/char/tpm/eventlog/tpm1.c @@ -115,6 +115,7 @@ 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; @@ -132,7 +133,6 @@ 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; } -- 2.39.5