Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: dlm: fix plock invalid read This patch fixes an invalid read showed by KASAN. A unlock will allocate a "struct plock_op" and a followed send_op() will append it to a global send_list data structure. In some cases a followed dev_read() moves it to recv_list and dev_write() will cast it to "struct plock_xop" and access fields which are only available in those structures. At this point an invalid read happens by accessing those fields. To fix this issue the "callback" field is moved to "struct plock_op" to indicate that a cast to "plock_xop" is allowed and does the additional "plock_xop" handling if set. Example of the KASAN output which showed the invalid read: [ 2064.296453] ================================================================== [ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm] [ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484 [ 2064.308168] [ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9 [ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 2064.311618] Call Trace: [ 2064.312218] dump_stack_lvl+0x56/0x7b [ 2064.313150] print_address_description.constprop.8+0x21/0x150 [ 2064.314578] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.315610] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.316595] kasan_report.cold.14+0x7f/0x11b [ 2064.317674] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.318687] dev_write+0x52b/0x5a0 [dlm] [ 2064.319629] ? dev_read+0x4a0/0x4a0 [dlm] [ 2064.320713] ? bpf_lsm_kernfs_init_security+0x10/0x10 [ 2064.321926] vfs_write+0x17e/0x930 [ 2064.322769] ? __fget_light+0x1aa/0x220 [ 2064.323753] ksys_write+0xf1/0x1c0 [ 2064.324548] ? __ia32_sys_read+0xb0/0xb0 [ 2064.325464] do_syscall_64+0x3a/0x80 [ 2064.326387] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.327606] RIP: 0033:0x7f807e4ba96f [ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48 [ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f [ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010 [ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001 [ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80 [ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001 [ 2064.342857] [ 2064.343226] Allocated by task 12438: [ 2064.344057] kasan_save_stack+0x1c/0x40 [ 2064.345079] __kasan_kmalloc+0x84/0xa0 [ 2064.345933] kmem_cache_alloc_trace+0x13b/0x220 [ 2064.346953] dlm_posix_unlock+0xec/0x720 [dlm] [ 2064.348811] do_lock_file_wait.part.32+0xca/0x1d0 [ 2064.351070] fcntl_setlk+0x281/0xbc0 [ 2064.352879] do_fcntl+0x5e4/0xfe0 [ 2064.354657] __x64_sys_fcntl+0x11f/0x170 [ 2064.356550] do_syscall_64+0x3a/0x80 [ 2064.358259] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.360745] [ 2064.361511] Last potentially related work creation: [ 2064.363957] kasan_save_stack+0x1c/0x40 [ 2064.365811] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.368100] call_rcu+0x11b/0xf70 [ 2064.369785] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.372404] receive_from_sock+0x290/0x770 [dlm] [ 2064.374607] process_recv_sockets+0x32/0x40 [dlm] [ 2064.377290] process_one_work+0x9a8/0x16e0 [ 2064.379357] worker_thread+0x87/0xbf0 [ 2064.381188] kthread+0x3ac/0x490 [ 2064.383460] ret_from_fork+0x22/0x30 [ 2064.385588] [ 2064.386518] Second to last potentially related work creation: [ 2064.389219] kasan_save_stack+0x1c/0x40 [ 2064.391043] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.393303] call_rcu+0x11b/0xf70 [ 2064.394885] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.397694] receive_from_sock+0x290/0x770 ---truncated---

Affected

ProductAffectedFixed inSource
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 2c55155cc365861044d9e6e80e342693e8805e332c55155cc365861044d9e6e80e342693e8805e33CNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 72f2f68970f9bdc252d59e119b385a6441b0b15572f2f68970f9bdc252d59e119b385a6441b0b155CNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 5a1765adf9855cf0f6d3f7e0eb4b78ca66f70dee5a1765adf9855cf0f6d3f7e0eb4b78ca66f70deeCNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 49cd9eb7b9a7b88124b31e31f8e539acaf1b3a6d49cd9eb7b9a7b88124b31e31f8e539acaf1b3a6dCNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 899bc4429174861122f0c236588700a4710c1fec899bc4429174861122f0c236588700a4710c1fecCNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < acdad5bc9827922ec2f2e84fd198718aa8e8ab92acdad5bc9827922ec2f2e84fd198718aa8e8ab92CNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 56aa8d1fbd02357f3bf81bdfba1cde87ce8402fc56aa8d1fbd02357f3bf81bdfba1cde87ce8402fcCNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < e421872fa17542cf33747071fb141b0130ce9ef7e421872fa17542cf33747071fb141b0130ce9ef7CNA
Linux586759f03e2e9031ac5589912a51a909ed53c30a – < 42252d0d2aa9b94d168241710a761588b395901942252d0d2aa9b94d168241710a761588b3959019CNA
Linux2.6.22–CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgit.kernel.org/stable/c/2c55155cc365861044d9e6e80e342693e8805e33refgit.kernel.org/stable/c/72f2f68970f9bdc252d59e119b385a6441b0b155refgit.kernel.org/stable/c/5a1765adf9855cf0f6d3f7e0eb4b78ca66f70deerefgit.kernel.org/stable/c/49cd9eb7b9a7b88124b31e31f8e539acaf1b3a6drefgit.kernel.org/stable/c/899bc4429174861122f0c236588700a4710c1fecrefgit.kernel.org/stable/c/acdad5bc9827922ec2f2e84fd198718aa8e8ab92refgit.kernel.org/stable/c/56aa8d1fbd02357f3bf81bdfba1cde87ce8402fcrefgit.kernel.org/stable/c/e421872fa17542cf33747071fb141b0130ce9ef7refgit.kernel.org/stable/c/42252d0d2aa9b94d168241710a761588b3959019