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authorLetu Ren <fantasquex@gmail.com>2021-11-12 20:06:41 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-10-12 09:51:24 +0200
commitce57f7b2e61404e28453cd75afa2a013c263c34f (patch)
tree1990b713e690766b4e81bc4041cbbf9682333c60 /drivers
parent5f2f005094963accab7c01f66b439f969a050a45 (diff)
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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')
-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 3d6b137314f3..bbc4d5890ae6 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;
}