aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorLetu Ren <fantasquex@gmail.com>2021-11-12 20:06:41 +0800
committerMartin K. Petersen <martin.petersen@oracle.com>2022-09-15 21:26:55 -0400
commitfbfe96869b782364caebae0445763969ddb6ea67 (patch)
tree3afce26c8d0a0c0a28ade92af01f43c7a6fdcc04
parent991df3dd5144f2e6b1c38b8d20ed3d4d21e20b34 (diff)
downloadlinux-fbfe96869b782364caebae0445763969ddb6ea67.tar.gz
scsi: qedf: Fix a UAF bug in __qedf_probe()
In __qedf_probe(), if qedf->cdev is NULL which means qed_ops->common->probe() failed, then the program will goto label err1, and scsi_host_put() will free lport->host pointer. Because the memory qedf points to is allocated by libfc_host_alloc(), it will be freed by scsi_host_put(). However, the if statement below label err0 only checks whether qedf is NULL but doesn't check whether the memory has been freed. So a UAF bug can occur. There are two ways to reach the statements below err0. The first one is described as before, "qedf" should be set to NULL. The second one is goto "err0" directly. In the latter scenario qedf hasn't been changed and it has the initial value NULL. As a result the if statement is not reachable in any situation. The KASAN logs are as follows: [ 2.312969] BUG: KASAN: use-after-free in __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] [ 2.312969] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 2.312969] Call Trace: [ 2.312969] dump_stack_lvl+0x59/0x7b [ 2.312969] print_address_description+0x7c/0x3b0 [ 2.312969] ? __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] __kasan_report+0x160/0x1c0 [ 2.312969] ? __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] kasan_report+0x4b/0x70 [ 2.312969] ? kobject_put+0x25d/0x290 [ 2.312969] kasan_check_range+0x2ca/0x310 [ 2.312969] __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] ? selinux_kernfs_init_security+0xdc/0x5f0 [ 2.312969] ? trace_rpm_return_int_rcuidle+0x18/0x120 [ 2.312969] ? rpm_resume+0xa5c/0x16e0 [ 2.312969] ? qedf_get_generic_tlv_data+0x160/0x160 [ 2.312969] local_pci_probe+0x13c/0x1f0 [ 2.312969] pci_device_probe+0x37e/0x6c0 Link: https://lore.kernel.org/r/20211112120641.16073-1-fantasquex@gmail.com Reported-by: Zheyu Ma <zheyuma97@gmail.com> Acked-by: Saurav Kashyap <skashyap@marvell.com> Co-developed-by: Wende Tan <twd2.me@gmail.com> Signed-off-by: Wende Tan <twd2.me@gmail.com> Signed-off-by: Letu Ren <fantasquex@gmail.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/qedf/qedf_main.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/scsi/qedf/qedf_main.c b/drivers/scsi/qedf/qedf_main.c
index 3d6b137314f3f..bbc4d5890ae6a 100644
--- a/drivers/scsi/qedf/qedf_main.c
+++ b/drivers/scsi/qedf/qedf_main.c
@@ -3686,11 +3686,6 @@ err2:
err1:
scsi_host_put(lport->host);
err0:
- if (qedf) {
- QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC, "Probe done.\n");
-
- clear_bit(QEDF_PROBING, &qedf->flags);
- }
return rc;
}