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| author | Usama Arif <usama.arif@linux.dev> | 2026-06-16 07:15:17 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-04 13:44:17 +0200 |
| commit | 99e6c712cc300883b8cbf03347d5359ec1a4d6dd (patch) | |
| tree | 7433e1f5fc4625f07fadf868e0f03467f1665651 | |
| parent | 0d35f9f194a858567a21017d69318a51e3a822b9 (diff) | |
| download | linux-99e6c712cc300883b8cbf03347d5359ec1a4d6dd.tar.gz linux-99e6c712cc300883b8cbf03347d5359ec1a4d6dd.zip | |
kernel/fork: clear PF_BLOCK_TS in copy_process()
commit fd38b75c4b43295b10d69772a46d1c74dbd6fc81 upstream.
PF_BLOCK_TS is only set in blk_time_get_ns() when current->plug is
non-NULL, and blk_finish_plug() clears it via __blk_flush_plug()
before NULLing the plug pointer. copy_process() breaks the
invariant by inheriting PF_BLOCK_TS from the parent while resetting
the child's plug to NULL.
Clear PF_BLOCK_TS alongside that assignment so callers can rely on
"PF_BLOCK_TS set implies current->plug != NULL" and dereference
current->plug unguarded.
Fixes: 06b23f92af87 ("block: update cached timestamp post schedule/preemption")
Cc: stable@vger.kernel.org
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Link: https://patch.msgid.link/20260616141604.328820-2-usama.arif@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/fork.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 1215d3f52c6d..8b1238d69291 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2230,6 +2230,7 @@ __latent_entropy struct task_struct *copy_process( #ifdef CONFIG_BLOCK p->plug = NULL; + p->flags &= ~PF_BLOCK_TS; #endif futex_init_task(p); |