Messages in this thread | | | Date | Mon, 19 Sep 2022 20:40:34 +0200 | Subject | Re: [PATCH -next 1/2] ext4: fix potential memory leak in ext4_fc_record_regions() | From | Damien Guibouret <> |
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Hello,
Le 19/09/2022 à 16:40, Ye Bin a écrit : > As krealloc may return NULL, in this case 'state->fc_regions' may not be > freed by krealloc, but 'state->fc_regions' already set NULL. Then will > lead to 'state->fc_regions' memory leak. > > Signed-off-by: Ye Bin <yebin10@huawei.com> > --- > fs/ext4/fast_commit.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c > index 9217a588afd1..cc8c8db075ba 100644 > --- a/fs/ext4/fast_commit.c > +++ b/fs/ext4/fast_commit.c > @@ -1677,15 +1677,17 @@ int ext4_fc_record_regions(struct super_block *sb, int ino, > if (replay && state->fc_regions_used != state->fc_regions_valid) > state->fc_regions_used = state->fc_regions_valid; > if (state->fc_regions_used == state->fc_regions_size) { > + struct ext4_fc_alloc_region *fc_regions; > + > state->fc_regions_size += > EXT4_FC_REPLAY_REALLOC_INCREMENT; > - state->fc_regions = krealloc( > - state->fc_regions, > - state->fc_regions_size * > - sizeof(struct ext4_fc_alloc_region), > - GFP_KERNEL); > - if (!state->fc_regions) > + fc_regions = krealloc(state->fc_regions, > + state->fc_regions_size * > + sizeof(struct ext4_fc_alloc_region), > + GFP_KERNEL); > + if (!fc_regions)
Would it not be safer to restore state->fc_regions_size to its previous value in that case to keep consistency between size value and allocated size (or to update state->fc_regions_size only after allocation as it is done in second part of this patch) ?
> return -ENOMEM; > + state->fc_regions = fc_regions; > } > region = &state->fc_regions[state->fc_regions_used++]; > region->ino = ino;
Regards,
Damien
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