Re: Kernel crash during video transcoding

On 2020-08-16 22:23, Alexandre Levy wrote:
> (kgdb) p *m
> $2 = {plinks = {q = {tqe_next = 0x578491b51dd60510, tqe_prev =
> 0xd78c11bd9dde8518}, s = {ss = {sle_next = 0x578491b51dd60510}}, memguard =
> {p = 6306325585301210384,
>        v = 15531808720989095192}, uma = {slab = 0x578491b51dd60510, zone =
> 0xd78c11bd9dde8518}}, listq = {tqe_next = 0xd78c11bd9dde8518, tqe_prev =
> 0x265bc92017d7aa38},
>    object = 0x2659c92217d5aa3a, pindex = 2758957463725517354, phys_addr =
> 2758957463725517354, md = {pv_list = {tqh_first = 0x2e49c1321fc5a22a,
> tqh_last = 0x3e4bd1300fc7b228},
>      pv_gen = 265794104, pat_mode = 1046204704}, ref_count = 257405624,
> busy_lock = 1054593440, a = {{flags = 4757, queue = 48 '0', act_count = 134
> '\206'}, _bits = 2251297429},
>    order = 98 'b', pool = 204 '\314', flags = 75 'K', oflags = 105 'i',
> psind = -107 '\225', segind = 18 '\022', valid = 48 '0', dirty = 134 '\206'}

This "m" structure looks freed.

It looks like a use after free issue.

Can you enter this in GDB:

set print pretty on

Then dump some more structures you can get hold of?

--HPS