CVE-2022-49983

In the Linux kernel, the following vulnerability has been resolved:

udmabuf: Set the DMA mask for the udmabuf device (v2)

If the DMA mask is not set explicitly, the following warning occurs

when the userspace tries to access the dma-buf via the CPU as

reported by syzbot here:

WARNING: CPU: 1 PID: 3595 at kernel/dma/mapping.c:188

__dma_map_sg_attrs+0x181/0x1f0 kernel/dma/mapping.c:188

Modules linked in:

CPU: 0 PID: 3595 Comm: syz-executor249 Not tainted

5.17.0-rc2-syzkaller-00316-g0457e5153e0e #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS

Google 01/01/2011

RIP: 0010:__dma_map_sg_attrs+0x181/0x1f0 kernel/dma/mapping.c:188

Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 71 4c 8b 3d c0

83 b5 0d e9 db fe ff ff e8 b6 0f 13 00 0f 0b e8 af 0f 13 00 <0f> 0b 45

31 e4 e9 54 ff ff ff e8 a0 0f 13 00 49 8d 7f 50 48 b8 00

RSP: 0018:ffffc90002a07d68 EFLAGS: 00010293

RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000

RDX: ffff88807e25e2c0 RSI: ffffffff81649e91 RDI: ffff88801b848408

RBP: ffff88801b848000 R08: 0000000000000002 R09: ffff88801d86c74f

R10: ffffffff81649d72 R11: 0000000000000001 R12: 0000000000000002

R13: ffff88801d86c680 R14: 0000000000000001 R15: 0000000000000000

FS: 0000555556e30300(0000) GS:ffff8880b9d00000(0000)

knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00000000200000cc CR3: 000000001d74a000 CR4: 00000000003506e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Call Trace:

<TASK>

dma_map_sgtable+0x70/0xf0 kernel/dma/mapping.c:264

get_sg_table.isra.0+0xe0/0x160 drivers/dma-buf/udmabuf.c:72

begin_cpu_udmabuf+0x130/0x1d0 drivers/dma-buf/udmabuf.c:126

dma_buf_begin_cpu_access+0xfd/0x1d0 drivers/dma-buf/dma-buf.c:1164

dma_buf_ioctl+0x259/0x2b0 drivers/dma-buf/dma-buf.c:363

vfs_ioctl fs/ioctl.c:51 [inline]

__do_sys_ioctl fs/ioctl.c:874 [inline]

__se_sys_ioctl fs/ioctl.c:860 [inline]

__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860

do_syscall_x64 arch/x86/entry/common.c:50 [inline]

do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae

RIP: 0033:0x7f62fcf530f9

Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007ffe3edab9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010

RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f62fcf530f9

RDX: 0000000020000200 RSI: 0000000040086200 RDI: 0000000000000006

RBP: 00007f62fcf170e0 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 00007f62fcf17170

R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

</TASK>

v2: Dont't forget to deregister if DMA mask setup fails.