From 4525458538ff5e5a4315fc85ac495adcb62e7724 Mon Sep 17 00:00:00 2001 From: Zhao Mengmeng Date: Fri, 30 Aug 2024 17:16:39 +0800 Subject: [PATCH] jfs: Fix uninit-value access of new_ea in ea_buffer syzbot reports that lzo1x_1_do_compress is using uninit-value: ===================================================== BUG: KMSAN: uninit-value in lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178 lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178 lzogeneric1x_1_compress+0x26a/0x11b0 lib/lzo/lzo1x_compress.c:333 lzo1x_1_compress+0x47/0x80 lib/lzo/lzo1x_compress.c:383 __lzo_compress crypto/lzo.c:58 [inline] lzo_scompress+0x98/0x180 crypto/lzo.c:79 scomp_acomp_comp_decomp+0x7c6/0xb90 scomp_acomp_compress+0x32/0x40 crypto/scompress.c:187 crypto_acomp_compress include/crypto/acompress.h:251 [inline] zswap_compress+0x368/0xad0 mm/zswap.c:927 zswap_store+0x1af3/0x2dd0 mm/zswap.c:1459 swap_writepage+0x11f/0x470 mm/page_io.c:198 shmem_writepage+0x1a75/0x1f70 mm/shmem.c:1536 pageout mm/vmscan.c:680 [inline] shrink_folio_list+0x577f/0x7cb0 mm/vmscan.c:1360 evict_folios+0x9bce/0xbc80 mm/vmscan.c:4580 try_to_shrink_lruvec+0x13a3/0x1750 mm/vmscan.c:4775 shrink_one+0x646/0xd20 mm/vmscan.c:4813 shrink_many mm/vmscan.c:4876 [inline] lru_gen_shrink_node mm/vmscan.c:4954 [inline] shrink_node+0x451a/0x50f0 mm/vmscan.c:5934 kswapd_shrink_node mm/vmscan.c:6762 [inline] balance_pgdat mm/vmscan.c:6954 [inline] kswapd+0x257e/0x4290 mm/vmscan.c:7223 kthread+0x3dd/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:122 [inline] iterate_and_advance2 include/linux/iov_iter.h:249 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] copy_page_from_iter_atomic+0x12bb/0x2ae0 lib/iov_iter.c:481 copy_folio_from_iter_atomic include/linux/uio.h:186 [inline] generic_perform_write+0x896/0x12e0 mm/filemap.c:4032 shmem_file_write_iter+0x2bd/0x2f0 mm/shmem.c:3074 do_iter_readv_writev+0x8a1/0xa40 vfs_iter_write+0x459/0xd50 fs/read_write.c:895 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+0x15ec/0x3750 drivers/block/loop.c:1945 loop_rootcg_workfn+0x2b/0x40 drivers/block/loop.c:1976 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312 worker_thread+0xea7/0x14d0 kernel/workqueue.c:3389 kthread+0x3dd/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: copy_to_dinode+0x881/0xb30 fs/jfs/jfs_imap.c:3158 diWrite+0x1bf5/0x1f00 fs/jfs/jfs_imap.c:790 txCommit+0xdb8/0x8cd0 fs/jfs/jfs_txnmgr.c:1255 __jfs_xattr_set+0x1b7/0x1f0 fs/jfs/xattr.c:936 jfs_xattr_set+0x79/0x90 fs/jfs/xattr.c:958 __vfs_setxattr+0x844/0x8b0 fs/xattr.c:200 __vfs_setxattr_noperm+0x22f/0xb00 fs/xattr.c:234 __vfs_setxattr_locked+0x441/0x480 fs/xattr.c:295 vfs_setxattr+0x294/0x650 fs/xattr.c:321 do_setxattr fs/xattr.c:629 [inline] __do_sys_fsetxattr fs/xattr.c:710 [inline] __se_sys_fsetxattr+0x7f0/0x980 fs/xattr.c:686 __x64_sys_fsetxattr+0xe4/0x150 fs/xattr.c:686 x64_sys_call+0x19c3/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:191 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: ea_put fs/jfs/xattr.c:639 [inline] __jfs_setxattr+0x185f/0x1ae0 fs/jfs/xattr.c:785 __jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934 jfs_xattr_set+0x79/0x90 fs/jfs/xattr.c:958 __vfs_setxattr+0x844/0x8b0 fs/xattr.c:200 __vfs_setxattr_noperm+0x22f/0xb00 fs/xattr.c:234 __vfs_setxattr_locked+0x441/0x480 fs/xattr.c:295 vfs_setxattr+0x294/0x650 fs/xattr.c:321 do_setxattr fs/xattr.c:629 [inline] __do_sys_fsetxattr fs/xattr.c:710 [inline] __se_sys_fsetxattr+0x7f0/0x980 fs/xattr.c:686 __x64_sys_fsetxattr+0xe4/0x150 fs/xattr.c:686 x64_sys_call+0x19c3/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:191 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 Local variable ea_buf created at: __jfs_setxattr+0x5d/0x1ae0 fs/jfs/xattr.c:662 __jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934 CPU: 0 UID: 0 PID: 81 Comm: kswapd0 Tainted: G W 6.11.0-rc5-syzkaller #0 Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ===================================================== The reason is ea_buf->new_ea is not initialized properly. Fix this by using memset to empty its content at the begining in ea_get(). Signed-off-by: Zhao Mengmeng --- fs/jfs/xattr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c index 2999ed5d83f5..0fb05e314edf 100644 --- a/fs/jfs/xattr.c +++ b/fs/jfs/xattr.c @@ -434,6 +434,8 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) int rc; int quota_allocation = 0; + memset(&ea_buf->new_ea, 0, sizeof(ea_buf->new_ea)); + /* When fsck.jfs clears a bad ea, it doesn't clear the size */ if (ji->ea.flag == 0) ea_size = 0; -- 2.43.0