KASAN has found a slab-out-of-bounds error in ses_enclosure_data_process().
[ 27.298092] BUG: KASAN: slab-out-of-bounds in ses_enclosure_data_process+0x919/0xe80 [ses]
[ 27.306407] Read of size 1 at addr ffff8807c99048b1 by task systemd-udevd/1563
[ 27.315173] CPU: 18 PID: 1563 Comm: systemd-udevd Not tainted 4.18.0-80.23.el8.x86_64+debug #1
[ 27.323835] Hardware name: HPE ProLiant XL450 Gen10/ProLiant XL450 Gen10, BIOS U40 10/02/2018
[ 27.332410] Call Trace:
:
[ 27.348557] kasan_report.cold.6+0x92/0x1a6
[ 27.352771] ses_enclosure_data_process+0x919/0xe80 [ses]
[ 27.358211] ? kfree+0xd6/0x2e0
[ 27.361376] ses_intf_add+0xa23/0xef1 [ses]
[ 27.365590] ? class_dev_iter_next+0x6c/0xc0
[ 27.370034] class_interface_register+0x298/0x400
[ 27.374769] ? tsc_cs_mark_unstable+0x60/0x60
[ 27.379163] ? class_dev_iter_exit+0x10/0x10
[ 27.384857] ? 0xffffffffc0838000
[ 27.389580] ses_init+0x12/0x1000 [ses]
[ 27.394832] do_one_initcall+0xe9/0x5fd
:
[ 27.562322] Allocated by task 1563:
[ 27.562330] kasan_kmalloc+0xbf/0xe0
[ 27.569433] __kmalloc+0x150/0x360
[ 27.572858] ses_intf_add+0x76a/0xef1 [ses]
[ 27.577068] class_interface_register+0x298/0x400
[ 27.581803] ses_init+0x12/0x1000 [ses]
[ 27.587053] do_one_initcall+0xe9/0x5fd
[ 27.592309] do_init_module+0x1f2/0x710
[ 27.597564] load_module+0x3e19/0x5910
[ 27.601336] __do_sys_init_module+0x1dd/0x260
[ 27.606673] do_syscall_64+0xa5/0x4a0
[ 27.610359] entry_SYSCALL_64_after_hwframe+0x6a/0xdf
:
[ 27.624932] The buggy address belongs to the object at ffff8807c9904400
which belongs to the cache kmalloc-2048 of size 2048
[ 27.637701] The buggy address is located 1201 bytes inside of
2048-byte region [ffff8807c9904400, ffff8807c9904c00)
[ 27.649683] The buggy address belongs to the page:
[ 27.654503] page:ffffea001f264000 count:1 mapcount:0 mapping:ffff880107c15d80 index:0x0 compound_mapcount: 0
[ 27.664393] flags: 0x17ffffc0008100(slab|head)
[ 27.668865] raw: 0017ffffc0008100 dead000000000100 dead000000000200 ffff880107c15d80
[ 27.676656] raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
[ 27.684444] page dumped because: kasan: bad access detected
The out-of-bounds memory access happens to ses_dev->page10 which has a
size of 1200 bytes in this case. The invalid memory access happens in:
600 if (addl_desc_ptr &&
601 /* only find additional descriptions for specific devices */
602 (type_ptr[0] == ENCLOSURE_COMPONENT_DEVICE ||
603 type_ptr[0] == ENCLOSURE_COMPONENT_ARRAY_DEVICE ||
604 type_ptr[0] == ENCLOSURE_COMPONENT_SAS_EXPANDER ||
605 /* these elements are optional */
606 type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_TARGET_PORT ||
607 type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT ||
608 type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS))
609 addl_desc_ptr += addl_desc_ptr[1] + 2; <-- here
To fix the out-of-bounds memory access, code is now added to make sure
that addl_desc_ptr will never point to an address outside of its bounds.
With this patch, the KASAN warning is gone.
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
drivers/scsi/ses.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 0fc39224ce1e..dbc9acc2df2f 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -605,9 +605,14 @@ static void ses_enclosure_data_process(struct enclosure_device *edev,
/* these elements are optional */
type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_TARGET_PORT ||
type_ptr[0] == ENCLOSURE_COMPONENT_SCSI_INITIATOR_PORT ||
- type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS))
+ type_ptr[0] == ENCLOSURE_COMPONENT_CONTROLLER_ELECTRONICS)) {
addl_desc_ptr += addl_desc_ptr[1] + 2;
+ /* Ensure no out-of-bounds memory access */
+ if (addl_desc_ptr >= ses_dev->page10 +
+ ses_dev->page10_len)
+ addl_desc_ptr = NULL;
+ }
}
}
kfree(buf);
--
2.18.1
