On 1/10/23 09:39, Alex Bennée wrote:
From: Emilio Cota<c...@braap.org>Fixes the appended use-after-free. The root cause is that during tb invalidation we use CPU_FOREACH, and therefore to safely free a vCPU we must wait for an RCU grace period to elapse. $ x86_64-linux-user/qemu-x86_64 tests/tcg/x86_64-linux-user/munmap-pthread ================================================================= ==1800604==ERROR: AddressSanitizer: heap-use-after-free on address 0x62d0005f7418 at pc 0x5593da6704eb bp 0x7f4961a7ac70 sp 0x7f4961a7ac60 READ of size 8 at 0x62d0005f7418 thread T2 #0 0x5593da6704ea in tb_jmp_cache_inval_tb ../accel/tcg/tb-maint.c:244 #1 0x5593da6704ea in do_tb_phys_invalidate ../accel/tcg/tb-maint.c:290 #2 0x5593da670631 in tb_phys_invalidate__locked ../accel/tcg/tb-maint.c:306 #3 0x5593da670631 in tb_invalidate_phys_page_range__locked ../accel/tcg/tb-maint.c:542 #4 0x5593da67106d in tb_invalidate_phys_range ../accel/tcg/tb-maint.c:614 #5 0x5593da6a64d4 in target_munmap ../linux-user/mmap.c:766 #6 0x5593da6dba05 in do_syscall1 ../linux-user/syscall.c:10105 #7 0x5593da6f564c in do_syscall ../linux-user/syscall.c:13329 #8 0x5593da49e80c in cpu_loop ../linux-user/x86_64/../i386/cpu_loop.c:233 #9 0x5593da6be28c in clone_func ../linux-user/syscall.c:6633 #10 0x7f496231cb42 in start_thread nptl/pthread_create.c:442 #11 0x7f49623ae9ff (/lib/x86_64-linux-gnu/libc.so.6+0x1269ff) 0x62d0005f7418 is located 28696 bytes inside of 32768-byte region [0x62d0005f0400,0x62d0005f8400) freed by thread T148 here: #0 0x7f49627b6460 in __interceptor_free ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:52 #1 0x5593da5ac057 in cpu_exec_unrealizefn ../cpu.c:180 #2 0x5593da81f851 (/home/cota/src/qemu/build/qemu-x86_64+0x484851) Signed-off-by: Emilio Cota<c...@braap.org> Message-Id:<20230109224954.161672-2-c...@braap.org> Signed-off-by: Alex Bennée<alex.ben...@linaro.org> --- accel/tcg/tb-jmp-cache.h | 1 + accel/tcg/cpu-exec.c | 3 +-- cpu.c | 11 ++++++++++- 3 files changed, 12 insertions(+), 3 deletions(-)
Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
