Bug 2395876 (CVE-2022-50342)
| Summary: | CVE-2022-50342 kernel: floppy: Fix memory leak in do_floppy_init() | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: floppy: Fix memory leak in do_floppy_init() A memory leak was reported when floppy_alloc_disk() failed in do_floppy_init(). unreferenced object 0xffff888115ed25a0 (size 8): comm "modprobe", pid 727, jiffies 4295051278 (age 25.529s) hex dump (first 8 bytes): 00 ac 67 5b 81 88 ff ff ..g[.... backtrace: [<000000007f457abb>] __kmalloc_node+0x4c/0xc0 [<00000000a87bfa9e>] blk_mq_realloc_tag_set_tags.part.0+0x6f/0x180 [<000000006f02e8b1>] blk_mq_alloc_tag_set+0x573/0x1130 [<0000000066007fd7>] 0xffffffffc06b8b08 [<0000000081f5ac40>] do_one_initcall+0xd0/0x4f0 [<00000000e26d04ee>] do_init_module+0x1a4/0x680 [<000000001bb22407>] load_module+0x6249/0x7110 [<00000000ad31ac4d>] __do_sys_finit_module+0x140/0x200 [<000000007bddca46>] do_syscall_64+0x35/0x80 [<00000000b5afec39>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 unreferenced object 0xffff88810fc30540 (size 32): comm "modprobe", pid 727, jiffies 4295051278 (age 25.529s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000007f457abb>] __kmalloc_node+0x4c/0xc0 [<000000006b91eab4>] blk_mq_alloc_tag_set+0x393/0x1130 [<0000000066007fd7>] 0xffffffffc06b8b08 [<0000000081f5ac40>] do_one_initcall+0xd0/0x4f0 [<00000000e26d04ee>] do_init_module+0x1a4/0x680 [<000000001bb22407>] load_module+0x6249/0x7110 [<00000000ad31ac4d>] __do_sys_finit_module+0x140/0x200 [<000000007bddca46>] do_syscall_64+0x35/0x80 [<00000000b5afec39>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 If the floppy_alloc_disk() failed, disks of current drive will not be set, thus the lastest allocated set->tag cannot be freed in the error handling path. A simple call graph shown as below: floppy_module_init() floppy_init() do_floppy_init() for (drive = 0; drive < N_DRIVE; drive++) blk_mq_alloc_tag_set() blk_mq_alloc_tag_set_tags() blk_mq_realloc_tag_set_tags() # set->tag allocated floppy_alloc_disk() blk_mq_alloc_disk() # error occurred, disks failed to allocated ->out_put_disk: for (drive = 0; drive < N_DRIVE; drive++) if (!disks[drive][0]) # the last disks is not set and loop break break; blk_mq_free_tag_set() # the latest allocated set->tag leaked Fix this problem by free the set->tag of current drive before jump to error handling path. [efremov: added stable list, changed title]