qemu-io crashes with SIGSEGV when did -c truncate 320000 on a image_fuzzer image

[R.Nageswara Sastry]

git is at HEAD a93ece47fd9edbd4558db24300056c9a57d3bcd4
This is on ppc64le architecture.

Re-production steps:

1. Copy the attached files named test.img to a directory
2. And customize the following command to point to the above directory and run the same.
# mv test.img copy.img
# qemu-io <path to>/copy.img -c "truncate 320000"

from gdb:
Program terminated with signal 11, Segmentation fault.
#0 0x000000001000e444 in refresh_total_sectors (bs=0x1fe86f60, hint=11648) at block.c:723
723 if (drv->bdrv_getlength) {
Missing separate debuginfos, use: debuginfo-install cyrus-sasl-lib-2.1.26-21.el7.ppc64le glib2-2.50.3-3.el7.ppc64le glibc-2.17-196.el7.ppc64le gmp-6.0.0-15.el7.ppc64le gnutls-3.3.26-9.el7.ppc64le keyutils-libs-1.5.8-3.el7.ppc64le krb5-libs-1.15.1-8.el7.ppc64le libaio-0.3.109-13.el7.ppc64le libcom_err-1.42.9-10.el7.ppc64le libcurl-7.29.0-42.el7.ppc64le libffi-3.0.13-18.el7.ppc64le libgcc-4.8.5-16.el7_4.1.ppc64le libidn-1.28-4.el7.ppc64le libselinux-2.5-11.el7.ppc64le libssh2-1.4.3-10.el7_2.1.ppc64le libstdc++-4.8.5-16.el7_4.1.ppc64le libtasn1-4.10-1.el7.ppc64le nettle-2.7.1-8.el7.ppc64le nspr-4.13.1-1.0.el7_3.ppc64le nss-3.28.4-15.el7_4.ppc64le nss-softokn-freebl-3.28.3-8.el7_4.ppc64le nss-util-3.28.4-3.el7.ppc64le openldap-2.4.44-5.el7.ppc64le openssl-libs-1.0.2k-8.el7.ppc64le p11-kit-0.23.5-3.el7.ppc64le pcre-8.32-17.el7.ppc64le zlib-1.2.7-17.el7.ppc64le
(gdb) bt
#0 0x000000001000e444 in refresh_total_sectors (bs=0x1fe86f60, hint=11648) at block.c:723
#1 0x000000001000fa10 in bdrv_open_driver (bs=0x1fe86f60, drv=0x102036f0 <bdrv_qcow2>, node_name=0x0, options=0x1fe8c240, open_flags=24578,
    errp=0x3fffea0fc920) at block.c:1153
#2 0x0000000010010480 in bdrv_open_common (bs=0x1fe86f60, file=0x1fe92540, options=0x1fe8c240, errp=0x3fffea0fc920) at block.c:1395
#3 0x0000000010013ac8 in bdrv_open_inherit (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x1fe8c240, flags=24578, parent=0x0, child_role=0x0,
    errp=0x3fffea0fcae0) at block.c:2616
#4 0x0000000010013e8c in bdrv_open (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x0, flags=16386, errp=0x3fffea0fcae0) at block.c:2698
#5 0x000000001008b6d4 in blk_new_open (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x0, flags=16386, errp=0x3fffea0fcae0)
    at block/block-backend.c:321
#6 0x000000001000a6ec in openfile (name=0x3fffea0ff661 "copy.img", flags=16386, writethrough=true, force_share=false, opts=0x0) at qemu-io.c:81
#7 0x000000001000c040 in main (argc=4, argv=0x3fffea0fd208) at qemu-io.c:624
(gdb) bt full
#0 0x000000001000e444 in refresh_total_sectors (bs=0x1fe86f60, hint=11648) at block.c:723
        drv = 0x0
#1 0x000000001000fa10 in bdrv_open_driver (bs=0x1fe86f60, drv=0x102036f0 <bdrv_qcow2>, node_name=0x0, options=0x1fe8c240, open_flags=24578,
    errp=0x3fffea0fc920) at block.c:1153
        local_err = 0x0
        ret = 0
        __PRETTY_FUNCTION__ = "bdrv_open_driver"
        __func__ = "bdrv_open_driver"
#2 0x0000000010010480 in bdrv_open_common (bs=0x1fe86f60, file=0x1fe92540, options=0x1fe8c240, errp=0x3fffea0fc920) at block.c:1395
        ret = 16383
        open_flags = 24578
        filename = 0x1fe8e2b1 "copy.img"
        driver_name = 0x1fe54810 "qcow2"
        node_name = 0x0
        discard = 0x0
        detect_zeroes = 0x0
        opts = 0x1fe93100
        drv = 0x102036f0 <bdrv_qcow2>
        local_err = 0x0
        __PRETTY_FUNCTION__ = "bdrv_open_common"
        __func__ = "bdrv_open_common"
#3 0x0000000010013ac8 in bdrv_open_inherit (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x1fe8c240, flags=24578, parent=0x0, child_role=0x0,
    errp=0x3fffea0fcae0) at block.c:2616
        ret = 512
        file = 0x1fe92540
        bs = 0x1fe86f60
        drv = 0x102036f0 <bdrv_qcow2>
        drvname = 0x0
        backing = 0x0
        local_err = 0x0
        snapshot_options = 0x0
        snapshot_flags = 0
        __PRETTY_FUNCTION__ = "bdrv_open_inherit"
        __func__ = "bdrv_open_inherit"
#4 0x0000000010013e8c in bdrv_open (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x0, flags=16386, errp=0x3fffea0fcae0) at block.c:2698
No locals.
#5 0x000000001008b6d4 in blk_new_open (filename=0x3fffea0ff661 "copy.img", reference=0x0, options=0x0, flags=16386, errp=0x3fffea0fcae0)
    at block/block-backend.c:321
        blk = 0x1fe79410
        bs = 0x0
        perm = 3
#6 0x000000001000a6ec in openfile (name=0x3fffea0ff661 "copy.img", flags=16386, writethrough=true, force_share=false, opts=0x0) at qemu-io.c:81
        local_err = 0x0
#7 0x000000001000c040 in main (argc=4, argv=0x3fffea0fd208) at qemu-io.c:624
        readonly = 0
        sopt = 0x101b2608 "hVc:d:f:rsnCmkt:T:U"
        lopt = {{name = 0x101b26d0 "driver", has_arg = 0, flag = 0x0, val = 104}, {name = 0x101b26d8 "help", has_arg = 0, flag = 0x0, val = 86}, {
            name = 0x101b26e0 "version", has_arg = 1, flag = 0x0, val = 99}, {name = 0x101b26e8 "cmd", has_arg = 1, flag = 0x0, val = 102}, {
            name = 0x101b26f0 "format", has_arg = 0, flag = 0x0, val = 114}, {name = 0x101b2700 "y", has_arg = 0, flag = 0x0, val = 115}, {
            name = 0x101b2710 "", has_arg = 0, flag = 0x0, val = 110}, {name = 0x101b2718 "nocache", has_arg = 0, flag = 0x0, val = 67}, {
---Type <return> to continue, or q <return> to quit---
            name = 0x101b2728 "read", has_arg = 0, flag = 0x0, val = 109}, {name = 0x101b2738 "", has_arg = 0, flag = 0x0, val = 107}, {
            name = 0x101b2748 "io", has_arg = 1, flag = 0x0, val = 100}, {name = 0x101b2750 "discard", has_arg = 1, flag = 0x0, val = 116}, {
            name = 0x101b2758 "cache", has_arg = 1, flag = 0x0, val = 84}, {name = 0x101b25e8 "object", has_arg = 1, flag = 0x0, val = 256}, {
            name = 0x101b2760 "trace", has_arg = 0, flag = 0x0, val = 257}, {name = 0x101b1c48 "force-share", has_arg = 0, flag = 0x0, val = 85}, {name = 0x0,
            has_arg = 0, flag = 0x0, val = 0}}
        c = -1
        opt_index = 0
        flags = 16386
        writethrough = true
        local_error = 0x0
        opts = 0x0
        format = 0x0
        trace_file = 0x0
        force_share = false
(gdb)
(gdb) quit

Will attach image_fuzzer image.

[Max Reitz (xanclic)]

Hi,

Thanks a lot for reporting this bug! I've found a fix and I'll send a patch once I've written a test case.

Max

[Thomas Huth (th-huth)]

Fix has been released with QEMU 2.11:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=791fff504cad4d935df