BUG/MEDIUM: htx: mark htx_sl as packed since it may be realigned
A test on MIPS64 revealed that the following reg tests would all
fail at the same place in htx_replace_stline() when updating
parts of the request line:
reg-tests/cache/if-modified-since.vtc
reg-tests/http-rules/h1or2_to_h1c.vtc
reg-tests/http-rules/http_after_response.vtc
reg-tests/http-rules/normalize_uri.vtc
reg-tests/http-rules/path_and_pathq.vtc
While the status line is normally aligned since it's the first block
of the HTX, it may become unaligned once replaced. The problem is, it
is a structure which contains some u16 and u32, and dereferencing them
on machines not natively supporting unaligned accesses makes them crash
or handle crap. Typically, MIPS/MIPS64/SPARC will crash, ARMv5 will
either crash or (more likely) return swapped values and do crap, and
RISCV will trap and turn to slow emulation.
We can assign the htx_sl struct the packed attribute, but then this
also causes the ints to fill the 2-bytes gap before them, always causing
unaligned accesses for this part on such machines. The patch does a bit
better, by explicitly filling this two-bytes hole, and packing the
struct.
This should be backported to all versions.
(cherry picked from commit 276cdc11e8d9509c0373a0acb9f580097c27d51a)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit efe13040d16d27407de92d1f0c9d0bbc80d608b3)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 7e1e152429aed65e22f02209d5db8ce741355f41)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 8f463916c07918c0acb193592982d0634fd0427b)
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
1 file changed