[PATCH 6.18 276/314] nvme: fix memory allocation in nvme_pr_read_keys()

Sasha Levin
2026-03-10T11:29:47Z

From: Sungwoo Kim <iam@sung-woo.kim>

[ Upstream commit c3320153769f05fd7fe9d840cb555dd3080ae424 ]

nvme_pr_read_keys() takes num_keys from userspace and uses it to
calculate the allocation size for rse via struct_size(). The upper
limit is PR_KEYS_MAX (64K).

A malicious or buggy userspace can pass a large num_keys value that
results in a 4MB allocation attempt at most, causing a warning in
the page allocator when the order exceeds MAX_PAGE_ORDER.

To fix this, use kvzalloc() instead of kzalloc().

This bug has the same reasoning and fix with the patch below:
https://lore.kernel.org/linux-block/20251212013510.3576091-1-kartikey406@gmail.com/

Warning log:
WARNING: mm/page_alloc.c:5216 at __alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216, CPU#1: syz-executor117/272
Modules linked in:
CPU: 1 UID: 0 PID: 272 Comm: syz-executor117 Not tainted 6.19.0 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:__alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216
Code: ff 83 bd a8 fe ff ff 0a 0f 86 69 fb ff ff 0f b6 1d f9 f9 c4 04 80 fb 01 0f 87 3b 76 30 ff 83 e3 01 75 09 c6 05 e4 f9 c4 04 01 <0f> 0b 48 c7 85 70 fe ff ff 00 00 00 00 e9 8f fd ff ff 31 c0 e9 0d
RSP: 0018:ffffc90000fcf450 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff920001f9ea0
RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000040dc0
RBP: ffffc90000fcf648 R08: ffff88800b6c3380 R09: 0000000000000001
R10: ffffc90000fcf840 R11: ffff88807ffad280 R12: 0000000000000000
R13: 0000000000040dc0 R14: 0000000000000001 R15: ffffc90000fcf620
FS: 0000555565db33c0(0000) GS:ffff8880be26c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000000c CR3: 0000000003b72000 CR4: 00000000000006f0
Call Trace:
<TASK>
alloc_pages_mpol+0x236/0x4d0 mm/mempolicy.c:2486
alloc_frozen_pages_noprof+0x149/0x180 mm/mempolicy.c:2557
___kmalloc_large_node+0x10c/0x140 mm/slub.c:5598
__kmalloc_large_node_noprof+0x25/0xc0 mm/slub.c:5629
__do_kmalloc_node mm/slub.c:5645 [inline]
__kmalloc_noprof+0x483/0x6f0 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
nvme_pr_read_keys+0x8f/0x4c0 drivers/nvme/host/pr.c:245
blkdev_pr_read_keys block/ioctl.c:456 [inline]
blkdev_common_ioctl+0x1b71/0x29b0 block/ioctl.c:730
blkdev_ioctl+0x299/0x700 block/ioctl.c:786
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x1bf/0x220 fs/ioctl.c:583
x64_sys_call+0x1280/0x21b0 mnt/fuzznvme_1/fuzznvme/linux-build/v6.19/./arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x71/0x330 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fb893d3108d
Code: 28 c3 e8 46 1e 00 00 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff61f2f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffff61f3138 RCX: 00007fb893d3108d
RDX: 0000000020000040 RSI: 00000000c01070ce RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffff61f3138
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffff61f3128 R14: 00007fb893dae530 R15: 0000000000000001
</TASK>

Fixes: 5fd96a4e15de (nvme: Add pr_ops read_keys support)
Acked-by: Chao Shi <cshi008@fiu.edu>
Acked-by: Weidong Zhu <weizhu@fiu.edu>
Acked-by: Dave Tian <daveti@purdue.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/pr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
index ad2ecc2f49a97..fe7dbe2648158 100644
--- a/drivers/nvme/host/pr.c
+++ b/drivers/nvme/host/pr.c
@@ -242,7 +242,7 @@ static int nvme_pr_read_keys(struct block_device *bdev,
if (rse_len > U32_MAX)
return -EINVAL;

- rse = kzalloc(rse_len, GFP_KERNEL);
+ rse = kvzalloc(rse_len, GFP_KERNEL);
if (!rse)
return -ENOMEM;

@@ -267,7 +267,7 @@ static int nvme_pr_read_keys(struct block_device *bdev,
}

free_rse:
- kfree(rse);
+ kvfree(rse);
return ret;
}

--
2.51.0