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| author | Peter Oberparleiter <oberpar@linux.ibm.com> | 2024-06-20 14:20:27 +0200 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2024-07-01 17:47:01 +0200 |
| commit | bf365071ea92b9579d5a272679b74052a5643e35 (patch) | |
| tree | 8620628c8a32de390466518634fe616ff1ce5c88 /drivers/s390/char | |
| parent | ecec74bbfc6fb1885355aa0337f3452146e8caff (diff) | |
| download | lwn-bf365071ea92b9579d5a272679b74052a5643e35.tar.gz lwn-bf365071ea92b9579d5a272679b74052a5643e35.zip | |
s390/sclp: Prevent release of buffer in I/O
When a task waiting for completion of a Store Data operation is
interrupted, an attempt is made to halt this operation. If this attempt
fails due to a hardware or firmware problem, there is a chance that the
SCLP facility might store data into buffers referenced by the original
operation at a later time.
Handle this situation by not releasing the referenced data buffers if
the halt attempt fails. For current use cases, this might result in a
leak of few pages of memory in case of a rare hardware/firmware
malfunction.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'drivers/s390/char')
| -rw-r--r-- | drivers/s390/char/sclp_sd.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/s390/char/sclp_sd.c b/drivers/s390/char/sclp_sd.c index 5aeb7e094a1c..322700b96207 100644 --- a/drivers/s390/char/sclp_sd.c +++ b/drivers/s390/char/sclp_sd.c @@ -324,8 +324,14 @@ static int sclp_sd_store_data(struct sclp_sd_data *result, u8 di) &esize); if (rc) { /* Cancel running request if interrupted */ - if (rc == -ERESTARTSYS) - sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL); + if (rc == -ERESTARTSYS) { + if (sclp_sd_sync(page, SD_EQ_HALT, di, 0, 0, NULL, NULL)) { + pr_warn("Could not stop Store Data request - leaking at least %zu bytes\n", + (size_t)dsize * PAGE_SIZE); + data = NULL; + asce = 0; + } + } vfree(data); goto out; } |