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authorLetu Ren <fantasquex@gmail.com>2021-11-12 15:06:41 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-10-15 08:55:52 +0300
commit034b30c311461a661de6da14c417e246179bb130 (patch)
treed26d25cd8a15b83584a8074fbe658b7cf87e9113 /drivers/scsi
parent29461bbe2d7f79c691476dd69156bc5951ee1aeb (diff)
downloadlinux-034b30c311461a661de6da14c417e246179bb130.tar.xz
scsi: qedf: Fix a UAF bug in __qedf_probe()
[ Upstream commit fbfe96869b782364caebae0445763969ddb6ea67 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/scsi')
-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 e64457f53da8..de5b6453827c 100644
--- a/drivers/scsi/qedf/qedf_main.c
+++ b/drivers/scsi/qedf/qedf_main.c
@@ -3671,11 +3671,6 @@ 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;
}