From f7384f90ecc7ae3b07f59678c2037787ec5122d0 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Tue, 25 Feb 2020 09:26:22 +0300 Subject: [PATCH] tpm: tpm2_bios_measurements_next should increase position index commit f9bf8adb55cd5a357b247a16aafddf8c97b276e0 upstream. If .next function does not change position index, following .show function will repeat output related to current position index. For /sys/kernel/security/tpm0/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/tpm2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c index b9aeda1..e741b11 100644 --- a/drivers/char/tpm/eventlog/tpm2.c +++ b/drivers/char/tpm/eventlog/tpm2.c @@ -94,6 +94,7 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v, size_t event_size; void *marker; + (*pos)++; event_header = log->bios_event_log; if (v == SEQ_START_TOKEN) { @@ -118,7 +119,6 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v, if (((v + event_size) >= limit) || (event_size == 0)) return NULL; - (*pos)++; return v; } -- 2.7.4