In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix race between searching chunks and release journal_head from buffer_head
Encountered a race between ocfs2_test_bg_bit_allocatable() and
jbd2_journal_put_journal_head() resulting in the below vmcore.
PID: 106879 TASK: ffff880244ba9c00 CPU: 2 COMMAND: “loop3”
Call trace:
panic
oops_end
no_context
__bad_area_nosemaphore
bad_area_nosemaphore
__do_page_fault
do_page_fault
page_fault
[exception RIP: ocfs2_block_group_find_clear_bits+316]
ocfs2_block_group_find_clear_bits [ocfs2]
ocfs2_cluster_group_search [ocfs2]
ocfs2_search_chain [ocfs2]
ocfs2_claim_suballoc_bits [ocfs2]
__ocfs2_claim_clusters [ocfs2]
ocfs2_claim_clusters [ocfs2]
ocfs2_local_alloc_slide_window [ocfs2]
ocfs2_reserve_local_alloc_bits [ocfs2]
ocfs2_reserve_clusters_with_limit [ocfs2]
ocfs2_reserve_clusters [ocfs2]
ocfs2_lock_refcount_allocators [ocfs2]
ocfs2_make_clusters_writable [ocfs2]
ocfs2_replace_cow [ocfs2]
ocfs2_refcount_cow [ocfs2]
ocfs2_file_write_iter [ocfs2]
lo_rw_aio
loop_queue_work
kthread_worker_fn
kthread
ret_from_fork
When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the
bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and
released the jounal head from the buffer head. Needed to take bit lock
for the bit ‘BH_JournalHead’ to fix this race.
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/ocfs2/suballoc.c"
],
"versions": [
{
"version": "1da177e4c3f4",
"lessThan": "5043fbd294f5",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f4",
"lessThan": "2e382600e885",
"status": "affected",
"versionType": "git"
},
{
"version": "1da177e4c3f4",
"lessThan": "6f1b228529ae",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/ocfs2/suballoc.c"
],
"versions": [
{
"version": "5.10.77",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.14.16",
"lessThanOrEqual": "5.14.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]