NetSight
medium5.5

CVE-2022-49802

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix null pointer dereference in ftrace_add_mod() The @ftrace_mod is allocated by kz…

Impact

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix null pointer dereference in ftrace_add_mod() The @ftrace_mod is allocated by kzalloc(), so both the members {prev,next} of @ftrace_mode->list are NULL, it's not a valid state to call list_del(). If kstrdup() for @ftrace_mod->{func|module} fails, it goes to @out_free tag and calls free_ftrace_mod() to destroy @ftrace_mod, then list_del() will write prev->next and next->prev, where null pointer dereference happens. BUG: kernel NULL pointer dereference, address: 0000000000000008 Oops: 0002 [#1] PREEMPT SMP NOPTI Call Trace: <TASK> ftrace_mod_callback+0x20d/0x220 ? do_filp_open+0xd9/0x140 ftrace_process_regex.isra.51+0xbf/0x130 ftrace_regex_write.isra.52.part.53+0x6e/0x90 vfs_write+0xee/0x3a0 ? __audit_filter_op+0xb1/0x100 ? auditd_test_task+0x38/0x50 ksys_write+0xa5/0xe0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Kernel panic - not syncing: Fatal exception So call INIT_LIST_HEAD() to initialize the list member to fix this issue.

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 4.13 before 4.14.300
from 4.15 before 4.19.267
from 4.20 before 5.4.225
from 5.5 before 5.10.156
from 5.11 before 5.15.80
from 5.16 before 6.0.10

Weakness classification

References