https://blog.omiilgo.com/tags/elf/ Recent content in Elf on Security Notes Hugo en-us Tue, 15 Sep 2026 09:00:00 +0800 https://blog.omiilgo.com/posts/elf-symbol-and-relocation-basics/ Tue, 15 Sep 2026 09:00:00 +0800 https://blog.omiilgo.com/posts/elf-symbol-and-relocation-basics/ Toy PIE: readelf -s / -r / -d / -S in one sitting. .dynsym UND vs .symtab, JUMP_SLOT vs RELATIVE, how a stripped copy still names puts. gdb bind check. https://blog.omiilgo.com/posts/packed-elf-init-array-dump/ Mon, 18 Jul 2022 09:30:00 +0800 https://blog.omiilgo.com/posts/packed-elf-init-array-dump/ Lab stub that mprotects RWX, XOR-decodes a 32-byte .text blob, restores r-x, then returns into real code. readelf of .init_array and PT_GNU_STACK, gdb break on mprotect, dump of the r-x region. https://blog.omiilgo.com/posts/binary-auditing-checklist/ Sat, 21 Aug 2021 16:00:00 +0800 https://blog.omiilgo.com/posts/binary-auditing-checklist/ First-pass checklist actually filled: checksec + readelf + objdump on a 60-line toy with gets/sprintf/printf(user). One-pager of mitigations, sinks, and the ASan crash. https://blog.omiilgo.com/posts/relro-got-plt-reading-notes/ Mon, 15 Jun 2020 09:00:00 +0800 https://blog.omiilgo.com/posts/relro-got-plt-reading-notes/ Partial vs Full RELRO measured on one toy: readelf FLAGS/GNU_RELRO, objdump of puts@plt, gdb GOT slot before and after bind, /proc maps of .got.plt. Companion to the lazy-binding lab. https://blog.omiilgo.com/posts/elf-got-plt-lazy-binding-lab/ Wed, 22 Apr 2020 11:20:00 +0800 https://blog.omiilgo.com/posts/elf-got-plt-lazy-binding-lab/ Lab walkthrough of lazy PLT binding on a PIE: readelf, objdump, GOT slot before/after the first call, Partial vs Full RELRO.