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authorPeilin Ye <peilin.ye@bytedance.com>2022-08-03 15:23:43 -0700
committerJens Axboe <axboe@kernel.dk>2022-08-04 08:33:54 -0600
commitf482aa98652795846cc55da98ebe331eb74f3d0b (patch)
tree6cb094583f2ef7c0d9d5bfeab129145e0fa07cd2 /include/linux/audit.h
parentff2557b7224ea9a19fb79eb4bd16d4deef57816a (diff)
audit, io_uring, io-wq: Fix memory leak in io_sq_thread() and io_wqe_worker()
Currently @audit_context is allocated twice for io_uring workers: 1. copy_process() calls audit_alloc(); 2. io_sq_thread() or io_wqe_worker() calls audit_alloc_kernel() (which is effectively audit_alloc()) and overwrites @audit_context, causing: BUG: memory leak unreferenced object 0xffff888144547400 (size 1024): <...> hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8135cfc3>] audit_alloc+0x133/0x210 [<ffffffff81239e63>] copy_process+0xcd3/0x2340 [<ffffffff8123b5f3>] create_io_thread+0x63/0x90 [<ffffffff81686604>] create_io_worker+0xb4/0x230 [<ffffffff81686f68>] io_wqe_enqueue+0x248/0x3b0 [<ffffffff8167663a>] io_queue_iowq+0xba/0x200 [<ffffffff816768b3>] io_queue_async+0x113/0x180 [<ffffffff816840df>] io_req_task_submit+0x18f/0x1a0 [<ffffffff816841cd>] io_apoll_task_func+0xdd/0x120 [<ffffffff8167d49f>] tctx_task_work+0x11f/0x570 [<ffffffff81272c4e>] task_work_run+0x7e/0xc0 [<ffffffff8125a688>] get_signal+0xc18/0xf10 [<ffffffff8111645b>] arch_do_signal_or_restart+0x2b/0x730 [<ffffffff812ea44e>] exit_to_user_mode_prepare+0x5e/0x180 [<ffffffff844ae1b2>] syscall_exit_to_user_mode+0x12/0x20 [<ffffffff844a7e80>] do_syscall_64+0x40/0x80 Then, 3. io_sq_thread() or io_wqe_worker() frees @audit_context using audit_free(); 4. do_exit() eventually calls audit_free() again, which is okay because audit_free() does a NULL check. As suggested by Paul Moore, fix it by deleting audit_alloc_kernel() and redundant audit_free() calls. Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring") Suggested-by: Paul Moore <paul@paul-moore.com> Cc: stable@vger.kernel.org Signed-off-by: Peilin Ye <peilin.ye@bytedance.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20220803222343.31673-1-yepeilin.cs@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/audit.h')
-rw-r--r--include/linux/audit.h5
1 files changed, 0 insertions, 5 deletions
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 00f7a80f1a3e..3608992848d3 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -285,7 +285,6 @@ static inline int audit_signal_info(int sig, struct task_struct *t)
/* These are defined in auditsc.c */
/* Public API */
extern int audit_alloc(struct task_struct *task);
-extern int audit_alloc_kernel(struct task_struct *task);
extern void __audit_free(struct task_struct *task);
extern void __audit_uring_entry(u8 op);
extern void __audit_uring_exit(int success, long code);
@@ -578,10 +577,6 @@ static inline int audit_alloc(struct task_struct *task)
{
return 0;
}
-static inline int audit_alloc_kernel(struct task_struct *task)
-{
- return 0;
-}
static inline void audit_free(struct task_struct *task)
{ }
static inline void audit_uring_entry(u8 op)