Vincent Fazio <[email protected]> writes:
> From: Vincent Fazio <[email protected]> > > Previously, if the build host's libc did not define MAP_FIXED_NOREPLACE > or if the running kernel didn't support that flag, it was possible for > pgd_find_hole_fallback to munmap an incorrect address which could lead to > SIGSEGV if the range happened to overlap with the mapped address of the > QEMU binary. > > mmap(0x1000, 22261224, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, > -1, 0) = 0x7f889d331000 > munmap(0x1000, 22261224) = 0 > --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x84b817} --- > ++ killed by SIGSEGV +++ > > Now, always munmap the address returned by mmap. > > Fixes: 2667e069e7b5 ("linux-user: don't use MAP_FIXED in > pgd_find_hole_fallback") > Signed-off-by: Vincent Fazio <[email protected]> Reviewed-by: Alex Bennée <[email protected]> -- Alex Bennée
