lsfd: avoid undefined behavior #2586
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Thank you. It looks good to me. I made the same mistakes in
@ t-8ch if you have time, can you apply the same fix to the above functions? |
Passing a pointer to a different datatype to tfind() then were inserted
evokes undefines behavior.
This triggers UBSAN as shown below.
Instead pass the proper structs.
```
../misc-utils/lsfd.c:513:27: runtime error: member access within misaligned address 0x7ffe9ee6495c for type 'struct proc', which requires 8 byte alignment
0x7ffe9ee6495c: note: pointer points here
1a 1a 1a 1a 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 d0 49 e6 9e fe 7f 00 00
^
#0 0x56159cfa4a3b in proc_tree_compare ../misc-utils/lsfd.c:513
util-linux#1 0x7f9dd4d2d743 in __tfind (/usr/lib/libc.so.6+0x10f743) (BuildId: 8bfe03f6bf9b6a6e2591babd0bbc266837d8f658)
util-linux#2 0x56159cfa4ac3 in get_proc ../misc-utils/lsfd.c:518
util-linux#3 0x56159cfe217b in anon_pidfd_get_name ../misc-utils/lsfd-unkn.c:203
util-linux#4 0x56159cfe1040 in unkn_fill_column ../misc-utils/lsfd-unkn.c:93
util-linux#5 0x56159cfaaa37 in fill_column ../misc-utils/lsfd.c:1178
util-linux#6 0x56159cfaaac5 in convert_file ../misc-utils/lsfd.c:1193
util-linux#7 0x56159cfaac4f in convert ../misc-utils/lsfd.c:1212
util-linux#8 0x56159cfb2b54 in main ../misc-utils/lsfd.c:2317
util-linux#9 0x7f9dd4c45ccf (/usr/lib/libc.so.6+0x27ccf) (BuildId: 8bfe03f6bf9b6a6e2591babd0bbc266837d8f658)
util-linux#10 0x7f9dd4c45d89 in __libc_start_main (/usr/lib/libc.so.6+0x27d89) (BuildId: 8bfe03f6bf9b6a6e2591babd0bbc266837d8f658)
util-linux#11 0x56159cfa3c34 in _start (util-linux/build-meson/lsfd+0x41c34) (BuildId: 35fece1a205f96a2dbfe7a0e93b658530de675c4)
```
Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
Done! |
|
LGTM. Thank you. |
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Passing a pointer to a pid_t to tfind() which expects it to be backed by a 'struct proc' evokes undefined behavior.
This triggers UBSAN as shown below.
Instead pass a proper 'struct proc'.
Cc @masatake