{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2021-47563", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nice: avoid bpf_prog refcount underflow\n\nIce driver has the routines for managing XDP resources that are shared\nbetween ndo_bpf op and VSI rebuild flow. The latter takes place for\nexample when user changes queue count on an interface via ethtool's\nset_channels().\n\nThere is an issue around the bpf_prog refcounting when VSI is being\nrebuilt - since ice_prepare_xdp_rings() is called with vsi->xdp_prog as\nan argument that is used later on by ice_vsi_assign_bpf_prog(), same\nbpf_prog pointers are swapped with each other. Then it is also\ninterpreted as an 'old_prog' which in turn causes us to call\nbpf_prog_put on it that will decrement its refcount.\n\nBelow splat can be interpreted in a way that due to zero refcount of a\nbpf_prog it is wiped out from the system while kernel still tries to\nrefer to it:\n\n[ 481.069429] BUG: unable to handle page fault for address: ffffc9000640f038\n[ 481.077390] #PF: supervisor read access in kernel mode\n[ 481.083335] #PF: error_code(0x0000) - not-present page\n[ 481.089276] PGD 100000067 P4D 100000067 PUD 1001cb067 PMD 106d2b067 PTE 0\n[ 481.097141] Oops: 0000 [#1] PREEMPT SMP PTI\n[ 481.101980] CPU: 12 PID: 3339 Comm: sudo Tainted: G OE 5.15.0-rc5+ #1\n[ 481.110840] Hardware name: Intel Corp. GRANTLEY/GRANTLEY, BIOS GRRFCRB1.86B.0276.D07.1605190235 05/19/2016\n[ 481.122021] RIP: 0010:dev_xdp_prog_id+0x25/0x40\n[ 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\n[ 481.148991] RSP: 0018:ffffc90007b63868 EFLAGS: 00010286\n[ 481.155034] RAX: 0000000000000000 RBX: ffff889080824000 RCX: 0000000000000000\n[ 481.163278] RDX: ffffc9000640f000 RSI: ffff889080824010 RDI: ffff889080824000\n[ 481.171527] RBP: ffff888107af7d00 R08: 0000000000000000 R09: ffff88810db5f6e0\n[ 481.179776] R10: 0000000000000000 R11: ffff8890885b9988 R12: ffff88810db5f4bc\n[ 481.188026] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n[ 481.196276] FS: 00007f5466d5bec0(0000) GS:ffff88903fb00000(0000) knlGS:0000000000000000\n[ 481.205633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 481.212279] CR2: ffffc9000640f038 CR3: 000000014429c006 CR4: 00000000003706e0\n[ 481.220530] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[ 481.228771] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n[ 481.237029] Call Trace:\n[ 481.239856] rtnl_fill_ifinfo+0x768/0x12e0\n[ 481.244602] rtnl_dump_ifinfo+0x525/0x650\n[ 481.249246] ? __alloc_skb+0xa5/0x280\n[ 481.253484] netlink_dump+0x168/0x3c0\n[ 481.257725] netlink_recvmsg+0x21e/0x3e0\n[ 481.262263] ____sys_recvmsg+0x87/0x170\n[ 481.266707] ? __might_fault+0x20/0x30\n[ 481.271046] ? _copy_from_user+0x66/0xa0\n[ 481.275591] ? iovec_from_user+0xf6/0x1c0\n[ 481.280226] ___sys_recvmsg+0x82/0x100\n[ 481.284566] ? sock_sendmsg+0x5e/0x60\n[ 481.288791] ? __sys_sendto+0xee/0x150\n[ 481.293129] __sys_recvmsg+0x56/0xa0\n[ 481.297267] do_syscall_64+0x3b/0xc0\n[ 481.301395] entry_SYSCALL_64_after_hwframe+0x44/0xae\n[ 481.307238] RIP: 0033:0x7f5466f39617\n[ 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\n[ 481.342944] RSP: 002b:00007ffedc7f4308 EFLAGS: 00000246 ORIG_RAX: 000000000000002f\n[ 481.361783] RAX: ffffffffffffffda RBX: 00007ffedc7f5460 RCX: 00007f5466f39617\n[ 481.380278] RDX: 0000000000000000 RSI: 00007ffedc7f5360 RDI: 0000000000000003\n[ 481.398500] RBP: 00007ffedc7f53f0 R08: 0000000000000000 R09: 000055d556f04d50\n[ 481.416463] R10: 0000000000000077 R11: 0000000000000246 R12: 00007ffedc7f5360\n[ 481.434131] R13: 00007ffedc7f5350 R14: 00007ffedc7f5344 R15: 0000000000000e98\n[ 481.451520] Modules linked in: ice\n---truncated---" } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "efc2214b6047", "version_value": "e65a8707b4cd" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "5.5", "status": "affected" }, { "version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.83", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.6", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/e65a8707b4cd756d26d246bb2b9fab06eebafac1", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/e65a8707b4cd756d26d246bb2b9fab06eebafac1" }, { "url": "https://git.kernel.org/stable/c/1f10b09ccc832698ef4624a6ab9a213b6ccbda76", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/1f10b09ccc832698ef4624a6ab9a213b6ccbda76" }, { "url": "https://git.kernel.org/stable/c/f65ee535df775a13a1046c0a0b2d72db342f8a5b", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/f65ee535df775a13a1046c0a0b2d72db342f8a5b" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }