#syz test
On Sat, Oct 5, 2024 at 8:02 PM syzbot <syzbot+01218003be74b5e1213a@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
Hello,
syzbot found the following issue on:
HEAD commit: e32cde8d2bd7 Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=16cf7dd0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b1fd45f2013d812f
dashboard link: https://syzkaller.appspot.com/bug?extid=01218003be74b5e1213a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11cf7dd0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11d06580580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/16d4da549bf4/disk-e32cde8d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a01bc9a0e174/vmlinux-e32cde8d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/93f4dfad6909/bzImage-e32cde8d.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/433ba0700154/mount_0.gz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+01218003be74b5e1213a@xxxxxxxxxxxxxxxxxxxxxxxxx
exFAT-fs (loop0): failed to load upcase table (idx : 0x00010000, chksum : 0x726052d3, utbl_chksum : 0xe619d30d)
=====================================================
BUG: KMSAN: uninit-value in __exfat_get_dentry_set+0x10ca/0x14d0 fs/exfat/dir.c:804
__exfat_get_dentry_set+0x10ca/0x14d0 fs/exfat/dir.c:804
exfat_get_dentry_set+0x58/0xec0 fs/exfat/dir.c:859
__exfat_write_inode+0x3c1/0xe30 fs/exfat/inode.c:46
__exfat_truncate+0x7f3/0xbb0 fs/exfat/file.c:211
exfat_truncate+0xee/0x2a0 fs/exfat/file.c:257
exfat_write_failed fs/exfat/inode.c:421 [inline]
exfat_direct_IO+0x5a3/0x900 fs/exfat/inode.c:485
generic_file_direct_write+0x275/0x6a0 mm/filemap.c:3977
__generic_file_write_iter+0x242/0x460 mm/filemap.c:4141
exfat_file_write_iter+0x894/0xfb0 fs/exfat/file.c:598
do_iter_readv_writev+0x88a/0xa30
vfs_writev+0x56a/0x14f0 fs/read_write.c:1064
do_pwritev fs/read_write.c:1165 [inline]
__do_sys_pwritev2 fs/read_write.c:1224 [inline]
__se_sys_pwritev2+0x280/0x470 fs/read_write.c:1215
__x64_sys_pwritev2+0x11f/0x1a0 fs/read_write.c:1215
x64_sys_call+0x2edb/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:329
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was stored to memory at:
memcpy_to_iter lib/iov_iter.c:65 [inline]
iterate_bvec include/linux/iov_iter.h:123 [inline]
iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
iterate_and_advance include/linux/iov_iter.h:328 [inline]
_copy_to_iter+0xe53/0x2b30 lib/iov_iter.c:185
copy_page_to_iter+0x419/0x880 lib/iov_iter.c:362
shmem_file_read_iter+0xa09/0x12b0 mm/shmem.c:3167
do_iter_readv_writev+0x88a/0xa30
vfs_iter_read+0x278/0x760 fs/read_write.c:923
lo_read_simple drivers/block/loop.c:283 [inline]
do_req_filebacked drivers/block/loop.c:516 [inline]
loop_handle_cmd drivers/block/loop.c:1910 [inline]
loop_process_work+0x20fc/0x3750 drivers/block/loop.c:1945
loop_rootcg_workfn+0x2b/0x40 drivers/block/loop.c:1976
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Uninit was stored to memory at:
memcpy_from_iter lib/iov_iter.c:73 [inline]
iterate_bvec include/linux/iov_iter.h:123 [inline]
iterate_and_advance2 include/linux/iov_iter.h:304 [inline]
iterate_and_advance include/linux/iov_iter.h:328 [inline]
__copy_from_iter lib/iov_iter.c:249 [inline]
copy_page_from_iter_atomic+0x12b7/0x3100 lib/iov_iter.c:481
copy_folio_from_iter_atomic include/linux/uio.h:201 [inline]
generic_perform_write+0x8d1/0x1080 mm/filemap.c:4066
shmem_file_write_iter+0x2ba/0x2f0 mm/shmem.c:3221
do_iter_readv_writev+0x88a/0xa30
vfs_iter_write+0x44d/0xd40 fs/read_write.c:988
lo_write_bvec drivers/block/loop.c:243 [inline]
lo_write_simple drivers/block/loop.c:264 [inline]
do_req_filebacked drivers/block/loop.c:511 [inline]
loop_handle_cmd drivers/block/loop.c:1910 [inline]
loop_process_work+0x15e6/0x3750 drivers/block/loop.c:1945
loop_rootcg_workfn+0x2b/0x40 drivers/block/loop.c:1976
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310
worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391
kthread+0x3e2/0x540 kernel/kthread.c:389
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Uninit was created at:
__alloc_pages_noprof+0x9d6/0xe70 mm/page_alloc.c:4756
alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265
alloc_pages_noprof mm/mempolicy.c:2345 [inline]
folio_alloc_noprof+0x1db/0x310 mm/mempolicy.c:2352
filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1010
__filemap_get_folio+0xac4/0x1550 mm/filemap.c:1952
block_write_begin+0x6e/0x2b0 fs/buffer.c:2226
exfat_write_begin+0xfb/0x400 fs/exfat/inode.c:434
exfat_extend_valid_size fs/exfat/file.c:553 [inline]
exfat_file_write_iter+0x474/0xfb0 fs/exfat/file.c:588
do_iter_readv_writev+0x88a/0xa30
vfs_writev+0x56a/0x14f0 fs/read_write.c:1064
do_pwritev fs/read_write.c:1165 [inline]
__do_sys_pwritev2 fs/read_write.c:1224 [inline]
__se_sys_pwritev2+0x280/0x470 fs/read_write.c:1215
__x64_sys_pwritev2+0x11f/0x1a0 fs/read_write.c:1215
x64_sys_call+0x2edb/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:329
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
CPU: 0 UID: 0 PID: 5188 Comm: syz-executor221 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
=====================================================
---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
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From a5923aca821c5b3a5d4980bd7d604062a5215dfc Mon Sep 17 00:00:00 2001
From: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
Date: Sat, 12 Oct 2024 21:04:41 +0530
Subject: [PATCH] fs: fix uinit
Fix the uninitialized symbol
Signed-off-by: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
---
fs/exfat/dir.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 7446bf09a..6efbb5787 100644
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -791,6 +791,7 @@ static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,
es->modified = false;
es->start_off = off;
es->bh = es->__bh;
+ memset(es->__bh, 0, sizeof(es->__bh));
bh = sb_bread(sb, sec);
if (!bh)
@@ -801,6 +802,12 @@ static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,
struct exfat_dentry *ep;
ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
+
+ if (!ep) {
+ brelse(bh);
+ return -EIO;
+ }
+
if (ep->type != EXFAT_FILE) {
brelse(bh);
return -EIO;
--
2.34.1
