diff options
| author | Tom Rix <trix@redhat.com> | 2022-04-11 13:47:56 -0400 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2022-04-18 22:48:31 -0400 |
| commit | faad6cebded8e0fd902b672f220449b93db479eb (patch) | |
| tree | a855e9f107491ca67eac889dab5b70b012910174 /drivers/scsi/sr_ioctl.c | |
| parent | 70a3baeec4e89736be932a60d682d7ae27556f5c (diff) | |
| download | lwn-faad6cebded8e0fd902b672f220449b93db479eb.tar.gz lwn-faad6cebded8e0fd902b672f220449b93db479eb.zip | |
scsi: sr: Do not leak information in ioctl
sr_ioctl.c uses this pattern:
result = sr_do_ioctl(cd, &cgc);
to-user = buffer[];
kfree(buffer);
return result;
Use of a buffer without checking leaks information. Check result and jump
over the use of buffer if there is an error.
result = sr_do_ioctl(cd, &cgc);
if (result)
goto err;
to-user = buffer[];
err:
kfree(buffer);
return result;
Additionally, initialize the buffer to zero.
This problem can be seen in the 2.4.0 kernel.
Link: https://lore.kernel.org/r/20220411174756.2418435-1-trix@redhat.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/sr_ioctl.c')
| -rw-r--r-- | drivers/scsi/sr_ioctl.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c index ddd00efc4882..fbdb5124d7f7 100644 --- a/drivers/scsi/sr_ioctl.c +++ b/drivers/scsi/sr_ioctl.c @@ -41,7 +41,7 @@ static int sr_read_tochdr(struct cdrom_device_info *cdi, int result; unsigned char *buffer; - buffer = kmalloc(32, GFP_KERNEL); + buffer = kzalloc(32, GFP_KERNEL); if (!buffer) return -ENOMEM; @@ -55,10 +55,13 @@ static int sr_read_tochdr(struct cdrom_device_info *cdi, cgc.data_direction = DMA_FROM_DEVICE; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; tochdr->cdth_trk0 = buffer[2]; tochdr->cdth_trk1 = buffer[3]; +err: kfree(buffer); return result; } @@ -71,7 +74,7 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, int result; unsigned char *buffer; - buffer = kmalloc(32, GFP_KERNEL); + buffer = kzalloc(32, GFP_KERNEL); if (!buffer) return -ENOMEM; @@ -86,6 +89,8 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, cgc.data_direction = DMA_FROM_DEVICE; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; tocentry->cdte_ctrl = buffer[5] & 0xf; tocentry->cdte_adr = buffer[5] >> 4; @@ -98,6 +103,7 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, tocentry->cdte_addr.lba = (((((buffer[8] << 8) + buffer[9]) << 8) + buffer[10]) << 8) + buffer[11]; +err: kfree(buffer); return result; } @@ -384,7 +390,7 @@ int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn) { Scsi_CD *cd = cdi->handle; struct packet_command cgc; - char *buffer = kmalloc(32, GFP_KERNEL); + char *buffer = kzalloc(32, GFP_KERNEL); int result; if (!buffer) @@ -400,10 +406,13 @@ int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn) cgc.data_direction = DMA_FROM_DEVICE; cgc.timeout = IOCTL_TIMEOUT; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; memcpy(mcn->medium_catalog_number, buffer + 9, 13); mcn->medium_catalog_number[13] = 0; +err: kfree(buffer); return result; } |