* [BUG] ufs: UBSAN shift-out-of-bounds in ufs_fill_super() at fs/ufs/super.c:1181
@ 2026-05-26 21:47 Farhad Alemi
2026-05-26 22:49 ` Al Viro
0 siblings, 1 reply; 3+ messages in thread
From: Farhad Alemi @ 2026-05-26 21:47 UTC (permalink / raw)
To: Al Viro; +Cc: Kees Cook, linux-fsdevel, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2734 bytes --]
Hello Al and the linux-fsdevel team,
I am reporting a UFS crash found by syzkaller. fs/ufs has no named
M: entry in MAINTAINERS, so I'm routing by commit-history affinity.
Summary:
Mounting a crafted UFS image drives ufs_fill_super() through scalar
derivation from on-disk fields. At fs/ufs/super.c:1181:
uspi->s_inopf = uspi->s_inopb >> uspi->s_fpbshift;
uspi->s_fpbshift is taken directly from the on-disk superblock
(usb1->fs_fragshift) and is not range-checked before being used as a
shift exponent. A crafted image with fs_fragshift = 0x08000000 reaches
this line and UBSAN reports the out-of-bounds shift; under panic_on_warn
this is promoted to a kernel panic.
This is distinct from the earlier UBSAN report in ubh_bread_uspi() at
fs/ufs/util.c:55 -- that one is on s_fshift; this one is on s_fpbshift.
Same general bug class (unvalidated on-disk shift exponent), different
code site.
Observed on:
- Linux v6.17.8 (where the bug was originally found) and verified still
present in linus/master at commit e8c2f9fdadee (v7.1-rc4-754-ge8c2f9fdadee),
x86_64, QEMU Q35
- UBSAN enabled; panic_on_warn set
- Trigger requires the ability to mount a crafted filesystem image,
normally CAP_SYS_ADMIN/root or an equivalent syzkaller test environment.
- The shift expression at fs/ufs/super.c:1181 is unchanged in linus/master
HEAD; bug remains reachable on current mainline.
Impact:
A crafted UFS image triggers a UBSAN shift-out-of-bounds during mount,
which panic_on_warn promotes to a kernel panic:
ufs: ufstype=old is supported read-only
UBSAN: shift-out-of-bounds in fs/ufs/super.c:1181:30
shift exponent 134217728 is too large for 32-bit type '__u32' (aka
'unsigned int')
Relevant stack:
__ubsan_handle_shift_out_of_bounds+0x385/0x410 lib/ubsan.c:494
ufs_fill_super+0x69a9/0x75c0 fs/ufs/super.c:1181
get_tree_bdev_flags+0x436/0x500 fs/super.c:1692
vfs_get_tree+0x94/0x2b0 fs/super.c:1815
do_new_mount+0x2a7/0xa00 fs/namespace.c:3816
__se_sys_mount+0x321/0x420 fs/namespace.c:4332
Expected behavior:
The crafted image should be rejected at mount with -EINVAL once
uspi->s_fpbshift is read from the superblock and found to be out of
range, before any shift expression consumes it.
Reproducer:
I attached the generated C reproducer as reproducer.c. I also attached the
syzkaller program as reproducer.syz and the console report as
crash-report.txt.
Novelty check:
I searched syzbot dashboard data across upstream, fixed, invalid, stable,
and Android namespaces, and searched lore.kernel.org for
"shift-out-of-bounds" + "ufs_fill_super", "fs/ufs/super.c:1181", and the
broader "UBSAN" + "fs/ufs/super.c". I did not find an exact match.
I appreciate your time and consideration.
Regards,
Farhad
[-- Attachment #2: crash-report.txt --]
[-- Type: text/plain, Size: 1855 bytes --]
mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
>>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
ufs: ufstype=old is supported read-only
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/ufs/super.c:1181:30
shift exponent 134217728 is too large for 32-bit type '__u32' (aka 'unsigned int')
CPU: 0 UID: 0 PID: 3605 Comm: syz.2.17 Not tainted 6.17.8 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x1a9/0x280 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
__ubsan_handle_shift_out_of_bounds+0x385/0x410 lib/ubsan.c:494
ufs_fill_super+0x69a9/0x75c0 fs/ufs/super.c:1181
get_tree_bdev_flags+0x436/0x500 fs/super.c:1692
vfs_get_tree+0x94/0x2b0 fs/super.c:1815
do_new_mount+0x2a7/0xa00 fs/namespace.c:3816
do_mount fs/namespace.c:4144 [inline]
__do_sys_mount fs/namespace.c:4355 [inline]
__se_sys_mount+0x321/0x420 fs/namespace.c:4332
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf0/0x390 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd992df91be
Code: 0f 1f 40 00 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef0ae8ed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffef0ae8f70 RCX: 00007fd992df91be
RDX: 0000200000000080 RSI: 0000200000000580 RDI: 00007ffef0ae8f30
RBP: 0000200000000080 R08: 00007ffef0ae8f70 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000580
R13: 00007ffef0ae8f30 R14: 0000000000000546 R15: 00002000000000c0
</TASK>
---[ end trace ]---
[-- Attachment #3: reproducer.c --]
[-- Type: application/octet-stream, Size: 22044 bytes --]
// autogenerated by syzkaller (https://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <setjmp.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/loop.h>
#ifndef __NR_memfd_create
#define __NR_memfd_create 319
#endif
static unsigned long long procid;
//% This code is derived from puff.{c,h}, found in the zlib development. The
//% original files come with the following copyright notice:
//% Copyright (C) 2002-2013 Mark Adler, all rights reserved
//% version 2.3, 21 Jan 2013
//% This software is provided 'as-is', without any express or implied
//% warranty. In no event will the author be held liable for any damages
//% arising from the use of this software.
//% Permission is granted to anyone to use this software for any purpose,
//% including commercial applications, and to alter it and redistribute it
//% freely, subject to the following restrictions:
//% 1. The origin of this software must not be misrepresented; you must not
//% claim that you wrote the original software. If you use this software
//% in a product, an acknowledgment in the product documentation would be
//% appreciated but is not required.
//% 2. Altered source versions must be plainly marked as such, and must not be
//% misrepresented as being the original software.
//% 3. This notice may not be removed or altered from any source distribution.
//% Mark Adler madler@alumni.caltech.edu
//% BEGIN CODE DERIVED FROM puff.{c,h}
#define MAXBITS 15
#define MAXLCODES 286
#define MAXDCODES 30
#define MAXCODES (MAXLCODES + MAXDCODES)
#define FIXLCODES 288
struct puff_state {
unsigned char* out;
unsigned long outlen;
unsigned long outcnt;
const unsigned char* in;
unsigned long inlen;
unsigned long incnt;
int bitbuf;
int bitcnt;
jmp_buf env;
};
static int puff_bits(struct puff_state* s, int need)
{
long val = s->bitbuf;
while (s->bitcnt < need) {
if (s->incnt == s->inlen)
longjmp(s->env, 1);
val |= (long)(s->in[s->incnt++]) << s->bitcnt;
s->bitcnt += 8;
}
s->bitbuf = (int)(val >> need);
s->bitcnt -= need;
return (int)(val & ((1L << need) - 1));
}
static int puff_stored(struct puff_state* s)
{
s->bitbuf = 0;
s->bitcnt = 0;
if (s->incnt + 4 > s->inlen)
return 2;
unsigned len = s->in[s->incnt++];
len |= s->in[s->incnt++] << 8;
if (s->in[s->incnt++] != (~len & 0xff) ||
s->in[s->incnt++] != ((~len >> 8) & 0xff))
return -2;
if (s->incnt + len > s->inlen)
return 2;
if (s->outcnt + len > s->outlen)
return 1;
for (; len--; s->outcnt++, s->incnt++) {
if (s->in[s->incnt])
s->out[s->outcnt] = s->in[s->incnt];
}
return 0;
}
struct puff_huffman {
short* count;
short* symbol;
};
static int puff_decode(struct puff_state* s, const struct puff_huffman* h)
{
int first = 0;
int index = 0;
int bitbuf = s->bitbuf;
int left = s->bitcnt;
int code = first = index = 0;
int len = 1;
short* next = h->count + 1;
while (1) {
while (left--) {
code |= bitbuf & 1;
bitbuf >>= 1;
int count = *next++;
if (code - count < first) {
s->bitbuf = bitbuf;
s->bitcnt = (s->bitcnt - len) & 7;
return h->symbol[index + (code - first)];
}
index += count;
first += count;
first <<= 1;
code <<= 1;
len++;
}
left = (MAXBITS + 1) - len;
if (left == 0)
break;
if (s->incnt == s->inlen)
longjmp(s->env, 1);
bitbuf = s->in[s->incnt++];
if (left > 8)
left = 8;
}
return -10;
}
static int puff_construct(struct puff_huffman* h, const short* length, int n)
{
int len;
for (len = 0; len <= MAXBITS; len++)
h->count[len] = 0;
int symbol;
for (symbol = 0; symbol < n; symbol++)
(h->count[length[symbol]])++;
if (h->count[0] == n)
return 0;
int left = 1;
for (len = 1; len <= MAXBITS; len++) {
left <<= 1;
left -= h->count[len];
if (left < 0)
return left;
}
short offs[MAXBITS + 1];
offs[1] = 0;
for (len = 1; len < MAXBITS; len++)
offs[len + 1] = offs[len] + h->count[len];
for (symbol = 0; symbol < n; symbol++)
if (length[symbol] != 0)
h->symbol[offs[length[symbol]]++] = symbol;
return left;
}
static int puff_codes(struct puff_state* s, const struct puff_huffman* lencode,
const struct puff_huffman* distcode)
{
static const short lens[29] = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13,
15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
67, 83, 99, 115, 131, 163, 195, 227, 258};
static const short lext[29] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
static const short dists[30] = {
1, 2, 3, 4, 5, 7, 9, 13, 17, 25,
33, 49, 65, 97, 129, 193, 257, 385, 513, 769,
1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
static const short dext[30] = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
int symbol;
do {
symbol = puff_decode(s, lencode);
if (symbol < 0)
return symbol;
if (symbol < 256) {
if (s->outcnt == s->outlen)
return 1;
if (symbol)
s->out[s->outcnt] = symbol;
s->outcnt++;
} else if (symbol > 256) {
symbol -= 257;
if (symbol >= 29)
return -10;
int len = lens[symbol] + puff_bits(s, lext[symbol]);
symbol = puff_decode(s, distcode);
if (symbol < 0)
return symbol;
unsigned dist = dists[symbol] + puff_bits(s, dext[symbol]);
if (dist > s->outcnt)
return -11;
if (s->outcnt + len > s->outlen)
return 1;
while (len--) {
if (dist <= s->outcnt && s->out[s->outcnt - dist])
s->out[s->outcnt] = s->out[s->outcnt - dist];
s->outcnt++;
}
}
} while (symbol != 256);
return 0;
}
static int puff_fixed(struct puff_state* s)
{
static int virgin = 1;
static short lencnt[MAXBITS + 1], lensym[FIXLCODES];
static short distcnt[MAXBITS + 1], distsym[MAXDCODES];
static struct puff_huffman lencode, distcode;
if (virgin) {
lencode.count = lencnt;
lencode.symbol = lensym;
distcode.count = distcnt;
distcode.symbol = distsym;
short lengths[FIXLCODES];
int symbol;
for (symbol = 0; symbol < 144; symbol++)
lengths[symbol] = 8;
for (; symbol < 256; symbol++)
lengths[symbol] = 9;
for (; symbol < 280; symbol++)
lengths[symbol] = 7;
for (; symbol < FIXLCODES; symbol++)
lengths[symbol] = 8;
puff_construct(&lencode, lengths, FIXLCODES);
for (symbol = 0; symbol < MAXDCODES; symbol++)
lengths[symbol] = 5;
puff_construct(&distcode, lengths, MAXDCODES);
virgin = 0;
}
return puff_codes(s, &lencode, &distcode);
}
static int puff_dynamic(struct puff_state* s)
{
static const short order[19] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5,
11, 4, 12, 3, 13, 2, 14, 1, 15};
int nlen = puff_bits(s, 5) + 257;
int ndist = puff_bits(s, 5) + 1;
int ncode = puff_bits(s, 4) + 4;
if (nlen > MAXLCODES || ndist > MAXDCODES)
return -3;
short lengths[MAXCODES];
int index;
for (index = 0; index < ncode; index++)
lengths[order[index]] = puff_bits(s, 3);
for (; index < 19; index++)
lengths[order[index]] = 0;
short lencnt[MAXBITS + 1], lensym[MAXLCODES];
struct puff_huffman lencode = {lencnt, lensym};
int err = puff_construct(&lencode, lengths, 19);
if (err != 0)
return -4;
index = 0;
while (index < nlen + ndist) {
int symbol;
int len;
symbol = puff_decode(s, &lencode);
if (symbol < 0)
return symbol;
if (symbol < 16)
lengths[index++] = symbol;
else {
len = 0;
if (symbol == 16) {
if (index == 0)
return -5;
len = lengths[index - 1];
symbol = 3 + puff_bits(s, 2);
} else if (symbol == 17)
symbol = 3 + puff_bits(s, 3);
else
symbol = 11 + puff_bits(s, 7);
if (index + symbol > nlen + ndist)
return -6;
while (symbol--)
lengths[index++] = len;
}
}
if (lengths[256] == 0)
return -9;
err = puff_construct(&lencode, lengths, nlen);
if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
return -7;
short distcnt[MAXBITS + 1], distsym[MAXDCODES];
struct puff_huffman distcode = {distcnt, distsym};
err = puff_construct(&distcode, lengths + nlen, ndist);
if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
return -8;
return puff_codes(s, &lencode, &distcode);
}
static int puff(unsigned char* dest, unsigned long* destlen,
const unsigned char* source, unsigned long sourcelen)
{
struct puff_state s = {
.out = dest,
.outlen = *destlen,
.outcnt = 0,
.in = source,
.inlen = sourcelen,
.incnt = 0,
.bitbuf = 0,
.bitcnt = 0,
};
int err;
if (setjmp(s.env) != 0)
err = 2;
else {
int last;
do {
last = puff_bits(&s, 1);
int type = puff_bits(&s, 2);
err = type == 0 ? puff_stored(&s)
: (type == 1 ? puff_fixed(&s)
: (type == 2 ? puff_dynamic(&s) : -1));
if (err != 0)
break;
} while (!last);
}
*destlen = s.outcnt;
return err;
}
//% END CODE DERIVED FROM puff.{c,h}
#define ZLIB_HEADER_WIDTH 2
static int puff_zlib_to_file(const unsigned char* source,
unsigned long sourcelen, int dest_fd)
{
if (sourcelen < ZLIB_HEADER_WIDTH)
return 0;
source += ZLIB_HEADER_WIDTH;
sourcelen -= ZLIB_HEADER_WIDTH;
const unsigned long max_destlen = 132 << 20;
void* ret = mmap(0, max_destlen, PROT_WRITE | PROT_READ,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (ret == MAP_FAILED)
return -1;
unsigned char* dest = (unsigned char*)ret;
unsigned long destlen = max_destlen;
int err = puff(dest, &destlen, source, sourcelen);
if (err) {
munmap(dest, max_destlen);
errno = -err;
return -1;
}
if (write(dest_fd, dest, destlen) != (ssize_t)destlen) {
munmap(dest, max_destlen);
return -1;
}
return munmap(dest, max_destlen);
}
static int setup_loop_device(unsigned char* data, unsigned long size,
const char* loopname, int* loopfd_p)
{
int err = 0, loopfd = -1;
int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
if (memfd == -1) {
err = errno;
goto error;
}
if (puff_zlib_to_file(data, size, memfd)) {
err = errno;
goto error_close_memfd;
}
loopfd = open(loopname, O_RDWR);
if (loopfd == -1) {
err = errno;
goto error_close_memfd;
}
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
if (errno != EBUSY) {
err = errno;
goto error_close_loop;
}
ioctl(loopfd, LOOP_CLR_FD, 0);
usleep(1000);
if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
err = errno;
goto error_close_loop;
}
}
close(memfd);
*loopfd_p = loopfd;
return 0;
error_close_loop:
close(loopfd);
error_close_memfd:
close(memfd);
error:
errno = err;
return -1;
}
static void reset_loop_device(const char* loopname)
{
int loopfd = open(loopname, O_RDWR);
if (loopfd == -1) {
return;
}
if (ioctl(loopfd, LOOP_CLR_FD, 0)) {
}
close(loopfd);
}
static long syz_mount_image(volatile long fsarg, volatile long dir,
volatile long flags, volatile long optsarg,
volatile long change_dir,
volatile unsigned long size, volatile long image)
{
unsigned char* data = (unsigned char*)image;
int res = -1, err = 0, need_loop_device = !!size;
char* mount_opts = (char*)optsarg;
char* target = (char*)dir;
char* fs = (char*)fsarg;
char* source = NULL;
char loopname[64];
if (need_loop_device) {
int loopfd;
memset(loopname, 0, sizeof(loopname));
snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
if (setup_loop_device(data, size, loopname, &loopfd) == -1)
return -1;
close(loopfd);
source = loopname;
}
mkdir(target, 0777);
char opts[256];
memset(opts, 0, sizeof(opts));
if (strlen(mount_opts) > (sizeof(opts) - 32)) {
}
strncpy(opts, mount_opts, sizeof(opts) - 32);
if (strcmp(fs, "iso9660") == 0) {
flags |= MS_RDONLY;
} else if (strncmp(fs, "ext", 3) == 0) {
bool has_remount_ro = false;
char* remount_ro_start = strstr(opts, "errors=remount-ro");
if (remount_ro_start != NULL) {
char after = *(remount_ro_start + strlen("errors=remount-ro"));
char before = remount_ro_start == opts ? '\0' : *(remount_ro_start - 1);
has_remount_ro = ((before == '\0' || before == ',') &&
(after == '\0' || after == ','));
}
if (strstr(opts, "errors=panic") || !has_remount_ro)
strcat(opts, ",errors=continue");
} else if (strcmp(fs, "xfs") == 0) {
strcat(opts, ",nouuid");
} else if (strncmp(fs, "gfs2", 4) == 0 &&
(strstr(opts, "errors=panic") || strstr(opts, "debug"))) {
strcat(opts, ",errors=withdraw");
}
res = mount(source, target, fs, flags, opts);
if (res == -1) {
err = errno;
goto error_clear_loop;
}
res = open(target, O_RDONLY | O_DIRECTORY);
if (res == -1) {
err = errno;
goto error_clear_loop;
}
if (change_dir) {
res = chdir(target);
if (res == -1) {
err = errno;
}
}
error_clear_loop:
if (need_loop_device)
reset_loop_device(loopname);
errno = err;
return res;
}
int main(void)
{
syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
/*fd=*/(intptr_t)-1, /*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
/*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
/*fd=*/(intptr_t)-1, /*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
/*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
/*fd=*/(intptr_t)-1, /*offset=*/0ul);
const char* reason;
(void)reason;
if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
}
// syz_mount_image$ufs arguments: [
// fs: ptr[in, buffer] {
// buffer: {75 66 73 00} (length 0x4)
// }
// dir: ptr[in, buffer] {
// buffer: {2e 2f 70 6d 30 39 30 36 00} (length 0x9)
// }
// flags: mount_flags = 0x0 (8 bytes)
// opts: ptr[in, fs_options[ufs_options]] {
// fs_options[ufs_options] {
// elems: array[fs_opt_elem[ufs_options]] {
// }
// common: array[fs_opt_elem[fs_options_common]] {
// }
// null: const = 0x0 (1 bytes)
// }
// }
// chdir: int8 = 0x1 (1 bytes)
// size: len = 0x546 (8 bytes)
// img: ptr[in, buffer] {
// buffer: (compressed buffer with length 0x546)
// }
// ]
// returns fd_dir
memcpy((void*)0x200000000080, "ufs\000", 4);
memcpy((void*)0x200000000580, "./pm0906\000", 9);
*(uint8_t*)0x2000000000c0 = 0;
memcpy(
(void*)0x200000000b40,
"\x78\x9c\xec\xdb\x3d\x8b\xd4\x40\x18\x07\xf0\x7f\x72\x2f\xae\x70\xe0\x22"
"\x36\x82\xc5\xd9\x58\x2e\x16\x16\x16\x36\x87\x5f\x41\xed\x0f\x3c\x41\xb0"
"\xbc\xe2\x0a\x0b\xad\xec\xac\x6d\xec\xfc\x60\x7e\x01\xe1\x4a\x11\x21\x92"
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"\xd7",
1350);
syz_mount_image(/*fs=*/0x200000000080, /*dir=*/0x200000000580, /*flags=*/0,
/*opts=*/0x2000000000c0, /*chdir=*/1, /*size=*/0x546,
/*img=*/0x200000000b40);
return 0;
}
[-- Attachment #4: reproducer.syz --]
[-- Type: application/octet-stream, Size: 2378 bytes --]
# {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}
syz_mount_image$ufs(&(0x7f0000000080), &(0x7f0000000580)='./pm0906\x00', 0x0, &(0x7f00000000c0), 0x1, 0x546, &(0x7f0000000b40)="$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")
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUG] ufs: UBSAN shift-out-of-bounds in ufs_fill_super() at fs/ufs/super.c:1181
2026-05-26 21:47 [BUG] ufs: UBSAN shift-out-of-bounds in ufs_fill_super() at fs/ufs/super.c:1181 Farhad Alemi
@ 2026-05-26 22:49 ` Al Viro
2026-05-26 23:02 ` Farhad Alemi
0 siblings, 1 reply; 3+ messages in thread
From: Al Viro @ 2026-05-26 22:49 UTC (permalink / raw)
To: Farhad Alemi; +Cc: Kees Cook, linux-fsdevel, linux-kernel
On Tue, May 26, 2026 at 02:47:30PM -0700, Farhad Alemi wrote:
> Hello Al and the linux-fsdevel team,
>
> I am reporting a UFS crash found by syzkaller. fs/ufs has no named
> M: entry in MAINTAINERS, so I'm routing by commit-history affinity.
Same comment as for your previous report, really. I'll resurrect
an old patch adding sanity checks to ufs_fill_super() (rejecting the
same things BSD does), will Cc you when it's posted. Might be a week
or so, though - plenty of shit on my platter at the moment.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [BUG] ufs: UBSAN shift-out-of-bounds in ufs_fill_super() at fs/ufs/super.c:1181
2026-05-26 22:49 ` Al Viro
@ 2026-05-26 23:02 ` Farhad Alemi
0 siblings, 0 replies; 3+ messages in thread
From: Farhad Alemi @ 2026-05-26 23:02 UTC (permalink / raw)
To: Al Viro; +Cc: Kees Cook, linux-fsdevel, linux-kernel
Sounds good, Al--thanks. Happy to test the series when you post it.
On Tue, May 26, 2026 at 3:49 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Tue, May 26, 2026 at 02:47:30PM -0700, Farhad Alemi wrote:
> > Hello Al and the linux-fsdevel team,
> >
> > I am reporting a UFS crash found by syzkaller. fs/ufs has no named
> > M: entry in MAINTAINERS, so I'm routing by commit-history affinity.
>
> Same comment as for your previous report, really. I'll resurrect
> an old patch adding sanity checks to ufs_fill_super() (rejecting the
> same things BSD does), will Cc you when it's posted. Might be a week
> or so, though - plenty of shit on my platter at the moment.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-05-26 23:02 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-05-26 21:47 [BUG] ufs: UBSAN shift-out-of-bounds in ufs_fill_super() at fs/ufs/super.c:1181 Farhad Alemi
2026-05-26 22:49 ` Al Viro
2026-05-26 23:02 ` Farhad Alemi
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