In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
fbdev: omap2: fix use-after-free in omapfb_mmap<\/p>\n
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that
\ncan lead to use-after-free:<\/p>\n
The fb_mmap() entry point holds mm_lock but not lock (fb_info->lock),
\nwhile ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock.
\nThis allows concurrent execution.<\/p>\n
In omapfb_mmap():
\n1. rg = omapfb_get_mem_region(ofbi->region); \/\/ Get old region ref
\n2. start = omapfb_get_region_paddr(ofbi); \/\/ Read from NEW region
\n3. len = fix->smem_len; \/\/ Read from NEW region
\n4. vm_iomap_memory(vma, start, len); \/\/ Map NEW region memory
\n5. atomic_inc(&rg->map_count); \/\/ Increment OLD region!<\/p>\n
Concurrently, OMAPFB_SETUP_PLANE can:
\n– Reassign ofbi->region = new_rg
\n– Update fix->smem_len
\n– OMAPFB_SETUP_MEM then checks NEW region’s map_count (0!) and frees it<\/p>\n
This leaves userspace with a mapping to freed physical memory.<\/p>\n
The fix is to read all required values (start, len) from the same
\nregion reference (rg) that will have its map_count incremented,
\npreventing the region from being freed while still mapped.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
fbdev: omap2: fix use-after-free in omapfb_mmap<\/p>\n
omapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that
\ncan lead to <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-14869","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/14869","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14869"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}