Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:EOL][EOL]loop: Check for overflow while configuring loop[EOL][EOL]The userspace can configure a loop using an ioctl call, wherein[EOL]a configuration of type loop_config is passed (see lo_ioctl()'s[EOL]case on line 1550 of drivers/block/loop.c). This proceeds to call[EOL]loop_configure() which in turn calls loop_set_status_from_info()[EOL](see line 1050 of loop.c), passing &config->info which is of type[EOL]loop_info64*. This function then sets the appropriate values, like[EOL]the offset.[EOL][EOL]loop_device has lo_offset of type loff_t (see line 52 of loop.c),[EOL]which is typdef-chained to long long, whereas loop_info64 has[EOL]lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h).[EOL][EOL]The function directly copies offset from info to the device as[EOL]follows (See line 980 of loop.c):[EOL]\tlo->lo_offset = info->lo_offset;[EOL][EOL]This results in an overflow, which triggers a warning in iomap_iter()[EOL]due to a call to iomap_iter_done() which has:[EOL]\tWARN_ON_ONCE(iter->iomap.offset > iter->pos);[EOL][EOL]Thus, check for negative value during loop_set_status_from_info().[EOL][EOL]Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e

CREATE(Triage):(User=lchen-cn) [CVE-2022-49993 (https://nvd.nist.gov/vuln/detail/CVE-2022-49993)