From: Fenghua Yu <fenghua.yu@intel.com>
To: "Vinod Koul" <vkoul@kernel.org>, "Dave Jiang" <dave.jiang@intel.com>
Cc: dmaengine@vger.kernel.org,
"linux-kernel" <linux-kernel@vger.kernel.org>,
Fenghua Yu <fenghua.yu@intel.com>, Tony Zhu <tony.zhu@intel.com>
Subject: [PATCH] dmaengine: idxd: Ensure safe user copy of completion record
Date: Fri, 9 Feb 2024 11:14:12 -0800 [thread overview]
Message-ID: <20240209191412.1050270-1-fenghua.yu@intel.com> (raw)
If CONFIG_HARDENED_USERCOPY is enabled, copying completion record from
event log cache to user triggers a kernel bug.
[ 1987.159822] usercopy: Kernel memory exposure attempt detected from SLUB object 'dsa0' (offset 74, size 31)!
[ 1987.170845] ------------[ cut here ]------------
[ 1987.176086] kernel BUG at mm/usercopy.c:102!
[ 1987.180946] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 1987.186866] CPU: 17 PID: 528 Comm: kworker/17:1 Not tainted 6.8.0-rc2+ #5
[ 1987.194537] Hardware name: Intel Corporation AvenueCity/AvenueCity, BIOS BHSDCRB1.86B.2492.D03.2307181620 07/18/2023
[ 1987.206405] Workqueue: wq0.0 idxd_evl_fault_work [idxd]
[ 1987.212338] RIP: 0010:usercopy_abort+0x72/0x90
[ 1987.217381] Code: 58 65 9c 50 48 c7 c2 17 85 61 9c 57 48 c7 c7 98 fd 6b 9c 48 0f 44 d6 48 c7 c6 b3 08 62 9c 4c 89 d1 49 0f 44 f3 e8 1e 2e d5 ff <0f> 0b 49 c7 c1 9e 42 61 9c 4c 89 cf 4d 89 c8 eb a9 66 66 2e 0f 1f
[ 1987.238505] RSP: 0018:ff62f5cf20607d60 EFLAGS: 00010246
[ 1987.244423] RAX: 000000000000005f RBX: 000000000000001f RCX: 0000000000000000
[ 1987.252480] RDX: 0000000000000000 RSI: ffffffff9c61429e RDI: 00000000ffffffff
[ 1987.260538] RBP: ff62f5cf20607d78 R08: ff2a6a89ef3fffe8 R09: 00000000fffeffff
[ 1987.268595] R10: ff2a6a89eed00000 R11: 0000000000000003 R12: ff2a66934849c89a
[ 1987.276652] R13: 0000000000000001 R14: ff2a66934849c8b9 R15: ff2a66934849c899
[ 1987.284710] FS: 0000000000000000(0000) GS:ff2a66b22fe40000(0000) knlGS:0000000000000000
[ 1987.293850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1987.300355] CR2: 00007fe291a37000 CR3: 000000010fbd4005 CR4: 0000000000f71ef0
[ 1987.308413] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1987.316470] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[ 1987.324527] PKRU: 55555554
[ 1987.327622] Call Trace:
[ 1987.330424] <TASK>
[ 1987.332826] ? show_regs+0x6e/0x80
[ 1987.336703] ? die+0x3c/0xa0
[ 1987.339988] ? do_trap+0xd4/0xf0
[ 1987.343662] ? do_error_trap+0x75/0xa0
[ 1987.347922] ? usercopy_abort+0x72/0x90
[ 1987.352277] ? exc_invalid_op+0x57/0x80
[ 1987.356634] ? usercopy_abort+0x72/0x90
[ 1987.360988] ? asm_exc_invalid_op+0x1f/0x30
[ 1987.365734] ? usercopy_abort+0x72/0x90
[ 1987.370088] __check_heap_object+0xb7/0xd0
[ 1987.374739] __check_object_size+0x175/0x2d0
[ 1987.379588] idxd_copy_cr+0xa9/0x130 [idxd]
[ 1987.384341] idxd_evl_fault_work+0x127/0x390 [idxd]
[ 1987.389878] process_one_work+0x13e/0x300
[ 1987.394435] ? __pfx_worker_thread+0x10/0x10
[ 1987.399284] worker_thread+0x2f7/0x420
[ 1987.403544] ? _raw_spin_unlock_irqrestore+0x2b/0x50
[ 1987.409171] ? __pfx_worker_thread+0x10/0x10
[ 1987.414019] kthread+0x107/0x140
[ 1987.417693] ? __pfx_kthread+0x10/0x10
[ 1987.421954] ret_from_fork+0x3d/0x60
[ 1987.426019] ? __pfx_kthread+0x10/0x10
[ 1987.430281] ret_from_fork_asm+0x1b/0x30
[ 1987.434744] </TASK>
The issue arises because event log cache is created using
kmem_cache_create() which is not suitable for user copy.
Fix the issue by creating event log cache with
kmem_cache_create_usercopy(), ensuring safe user copy.
Fixes: c2f156bf168f ("dmaengine: idxd: create kmem cache for event log fault items")
Reported-by: Tony Zhu <tony.zhu@intel.com>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
drivers/dma/idxd/init.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 14df1f1347a8..4954adc6bb60 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -343,7 +343,9 @@ static void idxd_cleanup_internals(struct idxd_device *idxd)
static int idxd_init_evl(struct idxd_device *idxd)
{
struct device *dev = &idxd->pdev->dev;
+ unsigned int evl_cache_size;
struct idxd_evl *evl;
+ const char *idxd_name;
if (idxd->hw.gen_cap.evl_support == 0)
return 0;
@@ -355,9 +357,16 @@ static int idxd_init_evl(struct idxd_device *idxd)
spin_lock_init(&evl->lock);
evl->size = IDXD_EVL_SIZE_MIN;
- idxd->evl_cache = kmem_cache_create(dev_name(idxd_confdev(idxd)),
- sizeof(struct idxd_evl_fault) + evl_ent_size(idxd),
- 0, 0, NULL);
+ idxd_name = dev_name(idxd_confdev(idxd));
+ evl_cache_size = sizeof(struct idxd_evl_fault) + evl_ent_size(idxd);
+ /*
+ * Since completion record in evl_cache will be copied to user
+ * when handling completion record page fault, need to create
+ * the cache suitable for user copy.
+ */
+ idxd->evl_cache = kmem_cache_create_usercopy(idxd_name, evl_cache_size,
+ 0, 0, 0, evl_cache_size,
+ NULL);
if (!idxd->evl_cache) {
kfree(evl);
return -ENOMEM;
--
2.37.1
next reply other threads:[~2024-02-09 19:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-09 19:14 Fenghua Yu [this message]
2024-02-09 20:15 ` [PATCH] dmaengine: idxd: Ensure safe user copy of completion record Dave Jiang
2024-02-09 21:53 ` Lijun Pan
2024-02-10 0:20 ` Fenghua Yu
2024-02-19 17:20 ` Fenghua Yu
2024-02-20 1:42 ` Lijun Pan
2024-02-20 1:43 ` Lijun Pan
2024-02-23 12:08 ` Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240209191412.1050270-1-fenghua.yu@intel.com \
--to=fenghua.yu@intel.com \
--cc=dave.jiang@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tony.zhu@intel.com \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).