[PATCH 4.4-cip 20/23] drm: fix signed integer overflow


Ben Hutchings <ben.hutchings@...>
 

From: Xie XiuQi <xiexiuqi@huawei.com>

commit ae0119f5f73b1e9cf7177fbbeea68d74c5751def upstream.

Use 1UL for unsigned long, or we'll meet a overflow issue with UBSAN.

[ 15.589489] UBSAN: Undefined behaviour in drivers/gpu/drm/drm_hashtab.c:145:35
[ 15.589500] signed integer overflow:
[ 15.589999] -2147483648 - 1 cannot be represented in type 'int'
[ 15.590434] CPU: 2 PID: 294 Comm: plymouthd Not tainted 3.10.0-327.28.3.el7.x86_64 #1
[ 15.590653] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 01/07/2011
[ 15.591001] 1ffff1000670fe83 000000000d6b385e ffff88003387f3e0 ffffffff81ee3140
[ 15.591028] ffff88003387f3f8 ffffffff81ee31fd ffffffffa032f460 ffff88003387f560
[ 15.591044] ffffffff81ee46e2 0000002d00000009 0000000000000001 0000000041b58ab3
[ 15.591059] Call Trace:
[ 15.591078] [<ffffffff81ee3140>] dump_stack+0x1e/0x20
[ 15.591093] [<ffffffff81ee31fd>] ubsan_epilogue+0x12/0x55
[ 15.591109] [<ffffffff81ee46e2>] handle_overflow+0x1ba/0x215
[ 15.591126] [<ffffffff81ee4528>] ? __ubsan_handle_negate_overflow+0x162/0x162
[ 15.591146] [<ffffffff8103416c>] ? print_context_stack+0x9c/0x160
[ 15.591163] [<ffffffff81031df2>] ? dump_trace+0x252/0x750
[ 15.591181] [<ffffffff81739023>] ? __list_add+0x93/0x160
[ 15.591197] [<ffffffff81ee4798>] __ubsan_handle_sub_overflow+0x2a/0x31
[ 15.591261] [<ffffffffa0282140>] drm_ht_just_insert_please+0x1e0/0x200 [drm]
[ 15.591290] [<ffffffffa0528c7a>] ttm_base_object_init+0x10a/0x270 [ttm]
[ 15.591316] [<ffffffffa052a34c>] ttm_vt_lock+0x28c/0x3a0 [ttm]
[ 15.591343] [<ffffffffa052a0c0>] ? ttm_write_lock+0x180/0x180 [ttm]
[ 15.591362] [<ffffffff81419526>] ? kasan_unpoison_shadow+0x36/0x50
[ 15.591379] [<ffffffff81419526>] ? kasan_unpoison_shadow+0x36/0x50
[ 15.591396] [<ffffffff81419526>] ? kasan_unpoison_shadow+0x36/0x50
[ 15.591413] [<ffffffff81419526>] ? kasan_unpoison_shadow+0x36/0x50
[ 15.591442] [<ffffffffa061cbe1>] vmw_master_set+0x121/0x470 [vmwgfx]
[ 15.591459] [<ffffffff811773a5>] ? __init_waitqueue_head+0x45/0x70
[ 15.591487] [<ffffffffa061cac0>] ? vmw_master_drop+0x310/0x310 [vmwgfx]
[ 15.591535] [<ffffffffa026946a>] drm_open+0x92a/0xc00 [drm]
[ 15.591563] [<ffffffffa0619ff0>] ? vmw_driver_open+0x170/0x170 [vmwgfx]
[ 15.591610] [<ffffffffa0268b40>] ? drm_poll+0xe0/0xe0 [drm]
[ 15.591661] [<ffffffffa02797b4>] drm_stub_open+0x224/0x330 [drm]
[ 15.591711] [<ffffffffa0279590>] ? drm_minor_acquire+0x240/0x240 [drm]
[ 15.591727] [<ffffffff8145fa8a>] chrdev_open+0x1fa/0x3f0
[ 15.591742] [<ffffffff8145f890>] ? cdev_put+0x50/0x50
[ 15.591761] [<ffffffff814f6dc3>] ? __fsnotify_parent+0x53/0x210
[ 15.591778] [<ffffffff8144fde1>] do_dentry_open+0x351/0x670
[ 15.591792] [<ffffffff8145f890>] ? cdev_put+0x50/0x50
[ 15.591807] [<ffffffff814503c2>] vfs_open+0xa2/0x170
[ 15.591824] [<ffffffff8147b5df>] do_last+0xccf/0x2c80
[ 15.591842] [<ffffffff8147a910>] ? filename_create+0x320/0x320
[ 15.591858] [<ffffffff81472549>] ? path_init+0x1b9/0xa90
[ 15.591875] [<ffffffff81472390>] ? mountpoint_last+0x9a0/0x9a0
[ 15.591894] [<ffffffff815f9ccf>] ? selinux_file_alloc_security+0xcf/0x130
[ 15.591911] [<ffffffff8147d777>] path_openat+0x1e7/0xcc0
[ 15.591927] [<ffffffff81031df2>] ? dump_trace+0x252/0x750
[ 15.591943] [<ffffffff8147d590>] ? do_last+0x2c80/0x2c80
[ 15.591959] [<ffffffff81739023>] ? __list_add+0x93/0x160
[ 15.591974] [<ffffffff8104b48d>] ? save_stack_trace+0x7d/0xb0
[ 15.591989] [<ffffffff81480824>] do_filp_open+0xa4/0x160
[ 15.592004] [<ffffffff81480780>] ? user_path_mountpoint_at+0x50/0x50
[ 15.592022] [<ffffffff8149d755>] ? __alloc_fd+0x175/0x300
[ 15.592039] [<ffffffff81453127>] do_sys_open+0x1b7/0x3f0
[ 15.592054] [<ffffffff81452f70>] ? filp_open+0x80/0x80
[ 15.592070] [<ffffffff81453392>] SyS_open+0x32/0x40
[ 15.592088] [<ffffffff81f08989>] system_call_fastpath+0x16/0x1b

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
[seanpaul tweaked subject to remove "gpu/"]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1473152138-25335-1-git-send-email-xiexiuqi@huawei.com
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
---
drivers/gpu/drm/drm_hashtab.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c
index c3b80fd65d62..fbbd9f0c2eef 100644
--- a/drivers/gpu/drm/drm_hashtab.c
+++ b/drivers/gpu/drm/drm_hashtab.c
@@ -142,7 +142,7 @@ int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *it
unsigned long add)
{
int ret;
- unsigned long mask = (1 << bits) - 1;
+ unsigned long mask = (1UL << bits) - 1;
unsigned long first, unshifted_key;

unshifted_key = hash_long(seed, bits);
--
2.10.2



--
Ben Hutchings
Software Developer, Codethink Ltd.

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