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| author | NeilBrown <neilb@suse.de> | 2021-02-25 17:22:29 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 10:26:48 +0100 |
| commit | b74e3493264f772d782612475ad028dac7ccaceb (patch) | |
| tree | 37879345aa9621eb533940a7b5c3c13eac8affc6 /arch/x86/mm | |
| parent | ebd5a480db0edd688519c1b997021d22e17a702c (diff) | |
| download | linux-stable-b74e3493264f772d782612475ad028dac7ccaceb.tar.gz linux-stable-b74e3493264f772d782612475ad028dac7ccaceb.tar.bz2 linux-stable-b74e3493264f772d782612475ad028dac7ccaceb.zip | |
x86: fix seq_file iteration for pat/memtype.c
commit 3d2fc4c082448e9c05792f9b2a11c1d5db408b85 upstream.
The memtype seq_file iterator allocates a buffer in the ->start and ->next
functions and frees it in the ->show function. The preferred handling for
such resources is to free them in the subsequent ->next or ->stop function
call.
Since Commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration
code and interface") there is no guarantee that ->show will be called
after ->next, so this function can now leak memory.
So move the freeing of the buffer to ->next and ->stop.
Link: https://lkml.kernel.org/r/161248539022.21478.13874455485854739066.stgit@noble1
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/pat.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index d9fbd4f69920..35b2e35c2203 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -1132,12 +1132,14 @@ static void *memtype_seq_start(struct seq_file *seq, loff_t *pos) static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos) { + kfree(v); ++*pos; return memtype_get_idx(*pos); } static void memtype_seq_stop(struct seq_file *seq, void *v) { + kfree(v); } static int memtype_seq_show(struct seq_file *seq, void *v) @@ -1146,7 +1148,6 @@ static int memtype_seq_show(struct seq_file *seq, void *v) seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type), print_entry->start, print_entry->end); - kfree(print_entry); return 0; } |