If a fresh array block is allocated during resize, the current in-memory set size should be increased by the size of the block, not replaced by it. Before the fix, adding entries to a hash set type, leading to a table resize, caused an inconsistent memory size to be reported. This becomes more obvious when swapping sets with similar sizes: # cat hash_ip_size.sh #!/bin/sh FAIL_RETRIES=10 tries=0 while [ ${tries} -lt ${FAIL_RETRIES} ]; do ipset create t1 hash:ip for i in `seq 1 4345`; do ipset add t1 1.2.$((i / 255)).$((i % 255)) done t1_init="$(ipset list t1|sed -n 's/Size in memory: \(.*\)/\1/p')" ipset create t2 hash:ip for i in `seq 1 4360`; do ipset add t2 1.2.$((i / 255)).$((i % 255)) done t2_init="$(ipset list t2|sed -n 's/Size in memory: \(.*\)/\1/p')" ipset swap t1 t2 t1_swap="$(ipset list t1|sed -n 's/Size in memory: \(.*\)/\1/p')" t2_swap="$(ipset list t2|sed -n 's/Size in memory: \(.*\)/\1/p')" ipset destroy t1 ipset destroy t2 tries=$((tries + 1)) if [ ${t1_init} -lt 10000 ] || [ ${t2_init} -lt 10000 ]; then echo "FAIL after ${tries} tries:" echo "T1 size ${t1_init}, after swap ${t1_swap}" echo "T2 size ${t2_init}, after swap ${t2_swap}" exit 1 fi done echo "PASS" # echo -n 'func hash_ip4_resize +p' > /sys/kernel/debug/dynamic_debug/control # ./hash_ip_size.sh [ 2035.018673] attempt to resize set t1 from 10 to 11, t 00000000fe6551fa [ 2035.078583] set t1 resized from 10 (00000000fe6551fa) to 11 (00000000172a0163) [ 2035.080353] Table destroy by resize 00000000fe6551fa FAIL after 4 tries: T1 size 9064, after swap 71128 T2 size 71128, after swap 9064 Reported-by: NOYB <JunkYardMail1@Frontier.com> Fixes: 9e41f26a505c ("netfilter: ipset: Count non-static extension memory for userspace") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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