From ec40484e03422cae02b73ea7f04263cfadf86a61 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Mon, 30 Jan 2017 18:18:00 +0300 Subject: [PATCH] files-reg: fix use-after-free in open_remap_ghost() Ghost file entry used right after it has been freed: ERROR: AddressSanitizer: heap-use-after-free on address 0x60700000dc50 READ of size 4 at 0x60700000dc50 thread T0 #0 0x46e819 in open_remap_ghost criu/files-reg.c:312 #1 0x46e819 in prepare_one_remap criu/files-reg.c:461 #2 0x46e819 in prepare_remaps criu/files-reg.c:507 #3 0x45af00 in root_prepare_shared criu/cr-restore.c:235 #4 0x45af00 in restore_task_with_children criu/cr-restore.c:1421 #5 0x7efc71e85f0c in clone (/lib64/libc.so.6+0xe7f0c) 0x60700000dc50 is located 32 bytes inside of 80-byte region [0x60700000dc30,0x60700000dc80) freed by thread T0 here: #0 0x7efc7305184a in __interceptor_free (/usr/lib/gcc/x86_64-pc-linux-gnu/5.4.0/libasan.so.2+0x9884a) #1 0x46e4df in open_remap_ghost criu/files-reg.c:309 #2 0x46e4df in prepare_one_remap criu/files-reg.c:461 #3 0x46e4df in prepare_remaps criu/files-reg.c:507 previously allocated by thread T0 here: #0 0x7efc73051b82 in malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/5.4.0/libasan.so.2+0x98b82) #1 0x7efc7277a8ea in protobuf_c_message_unpack (/usr/lib64/libprotobuf-c.so.1+0x48ea) #2 0xd528232002838017 () Just move freeing after the last 'gfe' usage to fix this. Fixes: d0097b2db03a ("files: Support ghost directories restore") travis-ci: success for files-reg: fix use-after-free in open_remap_ghost() Signed-off-by: Andrey Ryabinin Signed-off-by: Pavel Emelyanov --- criu/files-reg.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/criu/files-reg.c b/criu/files-reg.c index 73a1838c9..8089793ab 100644 --- a/criu/files-reg.c +++ b/criu/files-reg.c @@ -306,12 +306,13 @@ static int open_remap_ghost(struct reg_file_info *rfi, if (create_ghost(gf, gfe, img)) goto close_ifd; - ghost_file_entry__free_unpacked(gfe, NULL); close_image(img); gf->remap.is_dir = S_ISDIR(gfe->mode); gf->remap.uid = gfe->uid; gf->remap.gid = gfe->gid; + ghost_file_entry__free_unpacked(gfe, NULL); + return 0; close_ifd: