Messages in this thread | | | Date | Fri, 17 Dec 2021 10:49:01 +0300 | From | Dan Carpenter <> | Subject | [axboe-block:for-5.17/block 106/108] block/blk-ioc.c:307 set_task_ioprio() error: we previously assumed 'task->io_context' could be null (see line 300) |
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tree: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-5.17/block head: 5ef1630586317e92c9ebd7b4ce48f393b7ff790f commit: 5fc11eebb4a98df5324a4de369bb5ab7f0007ff7 [106/108] block: open code create_task_io_context in set_task_ioprio config: i386-randconfig-m021-20211216 (https://download.01.org/0day-ci/archive/20211217/202112171520.5hNnOM0q-lkp@intel.com/config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings: block/blk-ioc.c:307 set_task_ioprio() error: we previously assumed 'task->io_context' could be null (see line 300)
vim +307 block/blk-ioc.c
a411cd3cfdc5bb Christoph Hellwig 2021-12-09 271 int set_task_ioprio(struct task_struct *task, int ioprio) a411cd3cfdc5bb Christoph Hellwig 2021-12-09 272 { a411cd3cfdc5bb Christoph Hellwig 2021-12-09 273 int err; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 274 const struct cred *cred = current_cred(), *tcred; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 275 a411cd3cfdc5bb Christoph Hellwig 2021-12-09 276 rcu_read_lock(); a411cd3cfdc5bb Christoph Hellwig 2021-12-09 277 tcred = __task_cred(task); a411cd3cfdc5bb Christoph Hellwig 2021-12-09 278 if (!uid_eq(tcred->uid, cred->euid) && a411cd3cfdc5bb Christoph Hellwig 2021-12-09 279 !uid_eq(tcred->uid, cred->uid) && !capable(CAP_SYS_NICE)) { a411cd3cfdc5bb Christoph Hellwig 2021-12-09 280 rcu_read_unlock(); a411cd3cfdc5bb Christoph Hellwig 2021-12-09 281 return -EPERM; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 282 } a411cd3cfdc5bb Christoph Hellwig 2021-12-09 283 rcu_read_unlock(); a411cd3cfdc5bb Christoph Hellwig 2021-12-09 284 a411cd3cfdc5bb Christoph Hellwig 2021-12-09 285 err = security_task_setioprio(task, ioprio); a411cd3cfdc5bb Christoph Hellwig 2021-12-09 286 if (err) a411cd3cfdc5bb Christoph Hellwig 2021-12-09 287 return err; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 288 8472161b77c41d Christoph Hellwig 2021-12-09 289 task_lock(task); 8472161b77c41d Christoph Hellwig 2021-12-09 290 if (unlikely(!task->io_context)) { 8472161b77c41d Christoph Hellwig 2021-12-09 291 struct io_context *ioc; 8472161b77c41d Christoph Hellwig 2021-12-09 292 8472161b77c41d Christoph Hellwig 2021-12-09 293 task_unlock(task); 5fc11eebb4a98d Christoph Hellwig 2021-12-09 294 5fc11eebb4a98d Christoph Hellwig 2021-12-09 295 ioc = alloc_io_context(GFP_ATOMIC, NUMA_NO_NODE); 5fc11eebb4a98d Christoph Hellwig 2021-12-09 296 if (!ioc) 5fc11eebb4a98d Christoph Hellwig 2021-12-09 297 return -ENOMEM; 5fc11eebb4a98d Christoph Hellwig 2021-12-09 298 5fc11eebb4a98d Christoph Hellwig 2021-12-09 299 task_lock(task); 5fc11eebb4a98d Christoph Hellwig 2021-12-09 @300 if (task->io_context || (task->flags & PF_EXITING)) { ^^^^^^^^^^^^^^^^^^^^^^^^ Assume "task->io_context" is NULL but PF_EXITING is set.
5fc11eebb4a98d Christoph Hellwig 2021-12-09 301 kmem_cache_free(iocontext_cachep, ioc); 5fc11eebb4a98d Christoph Hellwig 2021-12-09 302 ioc = task->io_context; 5fc11eebb4a98d Christoph Hellwig 2021-12-09 303 } else { 5fc11eebb4a98d Christoph Hellwig 2021-12-09 304 task->io_context = ioc; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 305 } 8472161b77c41d Christoph Hellwig 2021-12-09 306 } 8472161b77c41d Christoph Hellwig 2021-12-09 @307 task->io_context->ioprio = ioprio; ^^^^^^^^^^^^^^^^^^ Unchecked dereference.
8472161b77c41d Christoph Hellwig 2021-12-09 308 task_unlock(task); 8472161b77c41d Christoph Hellwig 2021-12-09 309 return 0; a411cd3cfdc5bb Christoph Hellwig 2021-12-09 310 }
--- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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