Patch "fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev" has been added to the 4.19-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     fs-jfs-fix-ubsan-array-index-out-of-bounds-in-dballo.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 369b1936a7022319258d11058e05559240f13c1d
Author: Yogesh <yogi.kernel@xxxxxxxxx>
Date:   Thu Jun 22 00:07:03 2023 +0530

    fs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev
    
    [ Upstream commit 4e302336d5ca1767a06beee7596a72d3bdc8d983 ]
    
    Syzkaller reported the following issue:
    
    UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:1965:6
    index -84 is out of range for type 's8[341]' (aka 'signed char[341]')
    CPU: 1 PID: 4995 Comm: syz-executor146 Not tainted 6.4.0-rc6-syzkaller-00037-gb6dad5178cea #0
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
    Call Trace:
     <TASK>
     __dump_stack lib/dump_stack.c:88 [inline]
     dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
     ubsan_epilogue lib/ubsan.c:217 [inline]
     __ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
     dbAllocDmapLev+0x3e5/0x430 fs/jfs/jfs_dmap.c:1965
     dbAllocCtl+0x113/0x920 fs/jfs/jfs_dmap.c:1809
     dbAllocAG+0x28f/0x10b0 fs/jfs/jfs_dmap.c:1350
     dbAlloc+0x658/0xca0 fs/jfs/jfs_dmap.c:874
     dtSplitUp fs/jfs/jfs_dtree.c:974 [inline]
     dtInsert+0xda7/0x6b00 fs/jfs/jfs_dtree.c:863
     jfs_create+0x7b6/0xbb0 fs/jfs/namei.c:137
     lookup_open fs/namei.c:3492 [inline]
     open_last_lookups fs/namei.c:3560 [inline]
     path_openat+0x13df/0x3170 fs/namei.c:3788
     do_filp_open+0x234/0x490 fs/namei.c:3818
     do_sys_openat2+0x13f/0x500 fs/open.c:1356
     do_sys_open fs/open.c:1372 [inline]
     __do_sys_openat fs/open.c:1388 [inline]
     __se_sys_openat fs/open.c:1383 [inline]
     __x64_sys_openat+0x247/0x290 fs/open.c:1383
     do_syscall_x64 arch/x86/entry/common.c:50 [inline]
     do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
     entry_SYSCALL_64_after_hwframe+0x63/0xcd
    RIP: 0033:0x7f1f4e33f7e9
    Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
    RSP: 002b:00007ffc21129578 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
    RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f4e33f7e9
    RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
    RBP: 00007f1f4e2ff080 R08: 0000000000000000 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1f4e2ff110
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
     </TASK>
    
    The bug occurs when the dbAllocDmapLev()function attempts to access
    dp->tree.stree[leafidx + LEAFIND] while the leafidx value is negative.
    
    To rectify this, the patch introduces a safeguard within the
    dbAllocDmapLev() function. A check has been added to verify if leafidx is
    negative. If it is, the function immediately returns an I/O error, preventing
    any further execution that could potentially cause harm.
    
    Tested via syzbot.
    
    Reported-by: syzbot+853a6f4dfa3cf37d3aea@xxxxxxxxxxxxxxxxxxxxxxxxx
    Link: https://syzkaller.appspot.com/bug?extid=ae2f5a27a07ae44b0f17
    Signed-off-by: Yogesh <yogi.kernel@xxxxxxxxx>
    Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 07b9df8938f29..63ad6b1d575a5 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2040,6 +2040,9 @@ dbAllocDmapLev(struct bmap * bmp,
 	if (dbFindLeaf((dmtree_t *) & dp->tree, l2nb, &leafidx))
 		return -ENOSPC;
 
+	if (leafidx < 0)
+		return -EIO;
+
 	/* determine the block number within the file system corresponding
 	 * to the leaf at which free space was found.
 	 */



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux