CVE-2021-47563
"Intel Ice Network Driver BPF Prog Reference Count Underflow Vulnerability"
Description
In the Linux kernel, the following vulnerability has been resolved: ice: avoid bpf_prog refcount underflow Ice driver has the routines for managing XDP resources that are shared between ndo_bpf op and VSI rebuild flow. The latter takes place for example when user changes queue count on an interface via ethtool's set_channels(). There is an issue around the bpf_prog refcounting when VSI is being rebuilt - since ice_prepare_xdp_rings() is called with vsi->xdp_prog as an argument that is used later on by ice_vsi_assign_bpf_prog(), same bpf_prog pointers are swapped with each other. Then it is also interpreted as an 'old_prog' which in turn causes us to call bpf_prog_put on it that will decrement its refcount. Below splat can be interpreted in a way that due to zero refcount of a bpf_prog it is wiped out from the system while kernel still tries to refer to it: [ 481.069429] BUG: unable to handle page fault for address: ffffc9000640f038 [ 481.077390] #PF: supervisor read access in kernel mode [ 481.083335] #PF: error_code(0x0000) - not-present page [ 481.089276] PGD 100000067 P4D 100000067 PUD 1001cb067 PMD 106d2b067 PTE 0 [ 481.097141] Oops: 0000 [#1] PREEMPT SMP PTI [ 481.101980] CPU: 12 PID: 3339 Comm: sudo Tainted: G OE 5.15.0-rc5+ #1 [ 481.110840] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 481.122021] RIP: 0010:dev_xdp_prog_id+0x25/0x40 [ 481.127265] Code: 80 00 00 00 00 0f 1f 44 00 00 89 f6 48 c1 e6 04 48 01 fe 48 8b 86 98 08 00 00 48 85 c0 74 13 48 8b 50 18 31 c0 48 85 d2 74 07 <48> 8b 42 38 8b 40 20 c3 48 8b 96 90 08 00 00 eb e8 66 2e 0f 1f 84 [ 481.148991] RSP: 0018:ffffc90007b63868 EFLAGS: 00010286 [ 481.155034] RAX: 0000000000000000 RBX: ffff889080824000 RCX: 0000000000000000 [ 481.163278] RDX: ffffc9000640f000 RSI: ffff889080824010 RDI: ffff889080824000 [ 481.171527] RBP: ffff888107af7d00 R08: 0000000000000000 R09: ffff88810db5f6e0 [ 481.179776] R10: 0000000000000000 R11: ffff8890885b9988 R12: ffff88810db5f4bc [ 481.188026] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 481.196276] FS: 00007f5466d5bec0(0000) GS:ffff88903fb00000(0000) knlGS:0000000000000000 [ 481.205633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 481.212279] CR2: ffffc9000640f038 CR3: 000000014429c006 CR4: 00000000003706e0 [ 481.220530] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 481.228771] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 481.237029] Call Trace: [ 481.239856] rtnl_fill_ifinfo+0x768/0x12e0 [ 481.244602] rtnl_dump_ifinfo+0x525/0x650 [ 481.249246] ? __alloc_skb+0xa5/0x280 [ 481.253484] netlink_dump+0x168/0x3c0 [ 481.257725] netlink_recvmsg+0x21e/0x3e0 [ 481.262263] ____sys_recvmsg+0x87/0x170 [ 481.266707] ? __might_fault+0x20/0x30 [ 481.271046] ? _copy_from_user+0x66/0xa0 [ 481.275591] ? iovec_from_user+0xf6/0x1c0 [ 481.280226] ___sys_recvmsg+0x82/0x100 [ 481.284566] ? sock_sendmsg+0x5e/0x60 [ 481.288791] ? __sys_sendto+0xee/0x150 [ 481.293129] __sys_recvmsg+0x56/0xa0 [ 481.297267] do_syscall_64+0x3b/0xc0 [ 481.301395] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 481.307238] RIP: 0033:0x7f5466f39617 [ 481.311373] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb bd 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2f 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 [ 481.342944] RSP: 002b:00007ffedc7f4308 EFLAGS: 00000246 ORIG_RAX: 000000000000002f [ 481.361783] RAX: ffffffffffffffda RBX: 00007ffedc7f5460 RCX: 00007f5466f39617 [ 481.380278] RDX: 0000000000000000 RSI: 00007ffedc7f5360 RDI: 0000000000000003 [ 481.398500] RBP: 00007ffedc7f53f0 R08: 0000000000000000 R09: 000055d556f04d50 [ 481.416463] R10: 0000000000000077 R11: 0000000000000246 R12: 00007ffedc7f5360 [ 481.434131] R13: 00007ffedc7f5350 R14: 00007ffedc7f5344 R15: 0000000000000e98 [ 481.451520] Modules linked in: ice ---truncated---
INFO
Published Date :
May 24, 2024, 3:15 p.m.
Last Modified :
May 24, 2024, 6:09 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47563.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2021-47563 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47563 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 24, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: ice: avoid bpf_prog refcount underflow Ice driver has the routines for managing XDP resources that are shared between ndo_bpf op and VSI rebuild flow. The latter takes place for example when user changes queue count on an interface via ethtool's set_channels(). There is an issue around the bpf_prog refcounting when VSI is being rebuilt - since ice_prepare_xdp_rings() is called with vsi->xdp_prog as an argument that is used later on by ice_vsi_assign_bpf_prog(), same bpf_prog pointers are swapped with each other. Then it is also interpreted as an 'old_prog' which in turn causes us to call bpf_prog_put on it that will decrement its refcount. Below splat can be interpreted in a way that due to zero refcount of a bpf_prog it is wiped out from the system while kernel still tries to refer to it: [ 481.069429] BUG: unable to handle page fault for address: ffffc9000640f038 [ 481.077390] #PF: supervisor read access in kernel mode [ 481.083335] #PF: error_code(0x0000) - not-present page [ 481.089276] PGD 100000067 P4D 100000067 PUD 1001cb067 PMD 106d2b067 PTE 0 [ 481.097141] Oops: 0000 [#1] PREEMPT SMP PTI [ 481.101980] CPU: 12 PID: 3339 Comm: sudo Tainted: G OE 5.15.0-rc5+ #1 [ 481.110840] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016 [ 481.122021] RIP: 0010:dev_xdp_prog_id+0x25/0x40 [ 481.127265] Code: 80 00 00 00 00 0f 1f 44 00 00 89 f6 48 c1 e6 04 48 01 fe 48 8b 86 98 08 00 00 48 85 c0 74 13 48 8b 50 18 31 c0 48 85 d2 74 07 <48> 8b 42 38 8b 40 20 c3 48 8b 96 90 08 00 00 eb e8 66 2e 0f 1f 84 [ 481.148991] RSP: 0018:ffffc90007b63868 EFLAGS: 00010286 [ 481.155034] RAX: 0000000000000000 RBX: ffff889080824000 RCX: 0000000000000000 [ 481.163278] RDX: ffffc9000640f000 RSI: ffff889080824010 RDI: ffff889080824000 [ 481.171527] RBP: ffff888107af7d00 R08: 0000000000000000 R09: ffff88810db5f6e0 [ 481.179776] R10: 0000000000000000 R11: ffff8890885b9988 R12: ffff88810db5f4bc [ 481.188026] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 481.196276] FS: 00007f5466d5bec0(0000) GS:ffff88903fb00000(0000) knlGS:0000000000000000 [ 481.205633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 481.212279] CR2: ffffc9000640f038 CR3: 000000014429c006 CR4: 00000000003706e0 [ 481.220530] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 481.228771] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 481.237029] Call Trace: [ 481.239856] rtnl_fill_ifinfo+0x768/0x12e0 [ 481.244602] rtnl_dump_ifinfo+0x525/0x650 [ 481.249246] ? __alloc_skb+0xa5/0x280 [ 481.253484] netlink_dump+0x168/0x3c0 [ 481.257725] netlink_recvmsg+0x21e/0x3e0 [ 481.262263] ____sys_recvmsg+0x87/0x170 [ 481.266707] ? __might_fault+0x20/0x30 [ 481.271046] ? _copy_from_user+0x66/0xa0 [ 481.275591] ? iovec_from_user+0xf6/0x1c0 [ 481.280226] ___sys_recvmsg+0x82/0x100 [ 481.284566] ? sock_sendmsg+0x5e/0x60 [ 481.288791] ? __sys_sendto+0xee/0x150 [ 481.293129] __sys_recvmsg+0x56/0xa0 [ 481.297267] do_syscall_64+0x3b/0xc0 [ 481.301395] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 481.307238] RIP: 0033:0x7f5466f39617 [ 481.311373] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb bd 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2f 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 [ 481.342944] RSP: 002b:00007ffedc7f4308 EFLAGS: 00000246 ORIG_RAX: 000000000000002f [ 481.361783] RAX: ffffffffffffffda RBX: 00007ffedc7f5460 RCX: 00007f5466f39617 [ 481.380278] RDX: 0000000000000000 RSI: 00007ffedc7f5360 RDI: 0000000000000003 [ 481.398500] RBP: 00007ffedc7f53f0 R08: 0000000000000000 R09: 000055d556f04d50 [ 481.416463] R10: 0000000000000077 R11: 0000000000000246 R12: 00007ffedc7f5360 [ 481.434131] R13: 00007ffedc7f5350 R14: 00007ffedc7f5344 R15: 0000000000000e98 [ 481.451520] Modules linked in: ice ---truncated--- Added Reference kernel.org https://git.kernel.org/stable/c/e65a8707b4cd756d26d246bb2b9fab06eebafac1 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/1f10b09ccc832698ef4624a6ab9a213b6ccbda76 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/f65ee535df775a13a1046c0a0b2d72db342f8a5b [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47563 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47563
weaknesses.