ipvs: fix integer overflow in ftp helper port/address parsing

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ip_vs_ftp_get_addrport() accumulates decimal digits into a __u16
(hport) and into unsigned char (p[]) without checking for overflow.
A crafted FTP PASV/EPSV response with an over-long port or address
octet wraps the value, so the helper configures the data connection
with a truncated port/address.

The netfilter conntrack FTP helper had the same defect, fixed in
commit 2b413fc689 ("netfilter: nf_conntrack_ftp: avoid u16
overflows"). Apply the equivalent fix here: widen the port accumulator
to u32 and reject values above 65535, and reject address octets above
255.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Joas Antonio dos Santos <joasantonio108@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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Joas Antonio dos Santos 2026-08-13 15:34:24 -03:00 • committed by Pablo Neira Ayuso

parent 1e3b9e1c77

commit e625a9477d

1 changed files with 8 additions and 2 deletions

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net/netfilter/ipvs/ip_vs_ftp.c

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