smb: client: restore the data_offset bound in is_valid_oplock_break()

Browse source

Commit 83bfbd0bb9 ("cifs: Remove the RFC1002 header from smb_hdr")
changed the quantity this bound is measured against.  It used to be
srv->total_read minus the 4-byte RFC1002 preamble that total_read then
included, so it was the SMB message length.  The same commit stopped
counting the preamble, and the mechanical substitution to
srv->total_read - srv->pdu_size left an expression that is identically
zero: standard_receive3() reads MID_HEADER_SIZE() bytes and then exactly
pdu_length - MID_HEADER_SIZE() more, adding both to total_read.

len is therefore 0, the subtraction below it wraps, and no __u32
DataOffset can exceed the result, so the check from commit 097f5863b1
("cifs: read overflow in is_valid_oplock_break()") no longer rejects
anything.  Use total_read, which is now the message length on its own.

Fixes: 83bfbd0bb9 ("cifs: Remove the RFC1002 header from smb_hdr")
Cc: stable@kernel.org
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>

...

This commit is contained in:

Bryam Vargas 2026-07-28 13:06:13 -05:00 • committed by Paulo Alcantara

parent b96db32fed

commit ba22f575de

1 changed files with 2 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

fs/smb/client/smb1misc.c

View file